DOCUMENT NUMBER
S12EETX4KV0
Freescale Semiconductor, Inc.
EETX4K
Block Guide
V00.04
Original Release Date: 7 JUL 2003
Revised: 30 OCT 2003
Motorola, Inc.
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its
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including without limitation consequential or incidental damages. “Typical” parameters which may be provided in Motorola data sheets and/or specifications can and do vary in
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are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal
©Motorola, Inc., 2001
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Table of Contents
Glossary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
ESTAT — EEPROM Status Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
EADDR — EEPROM Address Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.3.10 EDATA — EEPROM Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
EEPROM Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
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Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Description of EEPROM Interrupt Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
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List of Figures
Figure 1-1 Module Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 3-1 EEPROM Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 3-2 EEPROM Clock Divider Register (ECLKDIV) . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 3-3 RESERVED1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 3-4 RESERVED2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 3-5 EEPROM Configuration Register (ECNFG) . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 3-6 EEPROM Protection Register (EPROT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 3-7 EEPROM Status Register (ESTAT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 3-8 EEPROM Command Register (ECMD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 3-9 RESERVED3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 3-10 EEPROM Address High Register (EADDRHI). . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 3-12 EEPROM Data High Register (EDATAHI). . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 3-13 EEPROM Data Low Register (EDATALO) . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 4-2 Example Erase Verify Command Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Figure 4-3 Example Program Command Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Figure 4-4 Example Sector Erase Command Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 4-5 Example Mass Erase Command Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figure 4-6 Example Sector Erase Abort Command Flow . . . . . . . . . . . . . . . . . . . . . . . . 37
Figure 4-7 Example Sector Modify Command Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Figure 4-8 EEPROM Interrupt Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
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List of Tables
Table 3-1 EEPROM Configuration Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Table 3-2 EEPROM Register Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 3-3 EEPROM Protection Address Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table 3-4 Valid EEPROM Command List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 4-1 EEPROM Command Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 4-2 EEPROM Interrupt Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
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Section 1 Introduction
1.1 Overview
This document describes the EETX4K module which includes a 4K byte EEPROM (Non-Volatile)
memory. The EEPROM memory may be read as either bytes, aligned words or misaligned words. Read
access time is one bus cycle for bytes and aligned words, and two bus cycles for misaligned words.
The EEPROM memory is ideal for data storage for single-supply applications allowing for field
reprogramming without requiring external voltage sources for program or erase. Program and erase
functions are controlled by a command driven interface. The EEPROM module supports both block erase
(all memory bytes) and sector erase (4 memory bytes). An erased bit reads ‘1’ and a programmed bit reads
‘0’. The high voltage required to program and erase the EEPROM memory is generated internally. It is not
possible to read from the EEPROM block while it is being erased or programmed.
NOTE: An EEPROM word (2 bytes) must be erased before being programmed. Cumulative
programming of bits within a word is not allowed.
1.1.1 Glossary
Command Write Sequence
A three-step MCU instruction sequence to execute built-in algorithms (including program and erase) on
the EEPROM memory.
1.2 Features
•
•
•
•
•
•
•
•
4K bytes of EEPROM memory divided into 1024 sectors of 4 bytes.
Automated program and erase algorithm.
Interrupts on EEPROM command completion and command buffer empty.
Fast sector erase and word program operation.
2-stage command pipeline.
Sector erase abort feature for critical interrupt response.
Flexible protection scheme to prevent accidental program or erase.
Single power supply for all EEPROM operations including program and erase.
1.3 Modes of Operation
•
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1.4 Block Diagram
EETX4K
EEPROM
Interface
Command
Interrupt
Command Pipeline
Request
EEPROM
cmd1
addr1
data1
cmd2
addr2
data2
2K * 16 Bits
sector 0
sector 1
Registers
Protection
sector 1023
Oscillator
Clock
Clock
Divider
EECLK
Figure 1-1 Module Block Diagram
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Section 3 Memory Map and Registers
3.1 Overview
This section describes the memory map and registers for the EEPROM module.
3.2 Module Memory Map
EEPROM memory addresses between logical addresses $0800 and $1000 with $0800 to $0BFF
representing 1K byte of paged EEPROM memory and $0C00 to $0FFF representing 1K byte of fixed
EEPROM memory. The EPROT register, described in section 3.3.5, can be set to protect the upper region
in the EEPROM memory from accidental program or erase. The EEPROM addresses covered by this
protectable region are shown in the EEPROM memory map. The default protection setting is stored in the
Table 3-1 EEPROM Configuration Field
EEPROM Memory
Address Offset
Size
(bytes)
Description
$_FFC
Reserved
1
1
2
EEPROM Protection byte
Refer to Section 3.3.5 EPROT —
$_FFD
$_FFE - $_FFF
Reserved
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ADDRESS OFFSET = $_00
EEPROM Registers
12 bytes
ADDRESS OFFSET = $_0B
EEPROM BASE + $_000
EEPROM Memory
3584 bytes (up to 4032 bytes)
+ $_E00
+ $_E40
+ _$E80
+ $_EC0
EEPROM Memory Protected Region
64, 128, 192, 256, 320, 384, 448, 512 bytes
+ $_F00
+ $_F40
+ $_F80
+ $_FC0
EEPROM Configuration Field
16 bytes ($_FFC - $_FFF)
EEPROM BASE + $_FFF
Figure 3-1 EEPROM Memory Map
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The EEPROM module also contains a set of 12 control and status registers located between EEPROM
register address offsets $_00 and $_0B. A summary of the EEPROM module registers is given in Table
Table 3-2 EEPROM Register Map
Address
Offset
Normal Mode
Access
Register Name
$_00
$_01
EEPROM Clock Divider Register (ECLKDIV)
R/W
R
1
RESERVED1
$_02
$_03
$_04
$_05
$_06
$_07
R
RESERVED2
EEPROM Configuration Register (ECNFG)
EEPROM Protection Register (EPROT)
EEPROM Status Register (ESTAT)
R/W
R/W
R/W
R/W
R
EEPROM Command Register (ECMD)
RESERVED3
$_08
$_09
R
R
R
R
EEPROM High Address Register (EADDRHI)
EEPROM Low Address Register (EADDRLO)
$_0A
EEPROM High Data Register (EDATAHI)
$_0B
EEPROM Low Data Register (EDATALO)
NOTES:
1. Intended for factory test purposes only.
NOTE: Register Address = EEPROM Control Register Base Address + Address Offset,
where the EEPROM Control Register Base Address is defined at the MCU level and
the Address Offset is defined at the EEPROM module level.
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3.3 Register Descriptions
3.3.1 ECLKDIV — EEPROM Clock Divider Register
The ECLKDIV register is used to control timed events in program and erase algorithms.
Address Offset: $_00
7
6
PRDIV8
0
5
EDIV5
0
4
EDIV4
0
3
EDIV3
0
2
EDIV2
0
1
EDIV1
0
0
EDIV0
0
R
W
EDIVLD
RESET:
0
= Unimplemented or Reserved
Figure 3-2 EEPROM Clock Divider Register (ECLKDIV)
All bits in the ECLKDIV register are readable, bits 6-0 are write once and bit 7 is not writable.
EDIVLD — Clock Divider Loaded.
1 = Register has been written to since the last reset.
0 = Register has not been written.
PRDIV8 — Enable Prescalar by 8.
1 = Enables a prescalar by 8, to divide the oscillator clock before feeding into the clock divider.
0 = The oscillator clock is directly fed into the ECLKDIV divider.
EDIV[5:0] — Clock Divider Bits.
The combination of PRDIV8 and EDIV[5:0] effectively divides the EEPROM module input oscillator
clock down to a frequency of 150kHz - 200kHz. The maximum divide ratio is 512. Please refer to
3.3.2 RESERVED1
This register is reserved for factory testing and is not accessible.
Address Offset: $_01
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
0
R
W
0
0
0
0
0
0
0
0
Reset:
= Unimplemented or Reserved
Figure 3-3 RESERVED1
All bits read zero and are not writable.
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3.3.3 RESERVED2
This register is reserved for factory testing and is not accessible.
Address Offset: $_02
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
0
R
W
Reset:
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 3-4 RESERVED2
All bits read zero and are not writable.
3.3.4 ECNFG — EEPROM Configuration Register
The ECNFG register enables the EEPROM interrupts.
Address Offset: $_03
7
CBEIE
0
6
CCIE
0
5
0
4
0
3
0
2
0
1
0
0
0
R
W
0
0
0
0
0
0
Reset:
= Unimplemented or Reserved
Figure 3-5 EEPROM Configuration Register (ECNFG)
CBEIE and CCIE bits are readable and writable while all remaining bits read zero and are not writable.
CBEIE — Command Buffer Empty Interrupt Enable.
The CBEIE bit enables an interrupt in case of an empty command buffer in the EEPROM module.
0 = Command Buffer Empty interrupt disabled.
CCIE — Command Complete Interrupt Enable.
The CCIE bit enables an interrupt in case all commands have been completed in the EEPROM module.
0 = Command Complete interrupt disabled.
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3.3.5 EPROT — EEPROM Protection Register
The EPROT register defines which EEPROM sectors are protected against program or erase operations.
Address Offset: $_04
7
EPOPEN
F
6
5
4
3
EPDIS
F
2
EPS2
F
1
EPS1
F
0
EPS0
F
R
W
RNV6
RNV5
RNV4
F
F
F
Reset:
= Unimplemented or Reserved
Figure 3-6 EEPROM Protection Register (EPROT)
All bits in the EPROT register are readable and writable except for RNV[6:4] which are only readable.
The EPOPEN and EPDIS bits can only be written to the protected state. The EPS bits can be written
anytime until bit EPDIS is cleared. If the EPOPEN bit is cleared, the state of the EPDIS and EPS bits is
irrelevant.
During the reset sequence, the EPROT register is loaded from the EEPROM Protection byte at address
will be loaded during the reset sequence, the EEPROM memory must be unprotected, then the EEPROM
Protection byte must be reprogrammed. Trying to alter data in any protected area in the EEPROM memory
will result in a protection violation error and the PVIOL flag will be set in the ESTAT register. The mass
erase of an EEPROM block is possible only when protection is fully disabled by setting the EPOPEN and
EPDIS bits.
EPOPEN — Opens the EEPROM for program or erase.
1 = The EEPROM sectors not protected are enabled for program or erase.
0 = The entire EEPROM memory is protected from program and erase.
RNV[6:4] — Reserved Non-Volatile Bits.
The RNV[6:4] bits should remain in the erased state “1” for future enhancements.
EPDIS — EEPROM Protection address range Disable.
The EPDIS bit determines whether there is a protected area in a specific region of the EEPROM
memory ending with address offset $_FFF.
1 = Protection disabled.
0 = Protection enabled.
EPS[2:0] — EEPROM Protection Address Size.
only be written to while the EPDIS bit is set.
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Table 3-3 EEPROM Protection Address Range
Address Offset
EPS[2:0]
Protected Size
Range
000
001
010
011
100
101
110
111
$_FC0-$_FFF
$_F80-$_FFF
$_F40-$_FFF
$_F00-$_FFF
$_EC0-$_FFF
$_E80-$_FFF
$_E40-$_FFF
$_E00-$_FFF
64 bytes
128 bytes
192 bytes
256 bytes
320 bytes
384 bytes
448 bytes
512 bytes
3.3.6 ESTAT — EEPROM Status Register
The ESTAT register defines the operational status of the module.
Address Offset: $_05
7
CBEIF
1
6
5
PVIOL
0
4
ACCERR
0
3
0
2
1
0
0
0
R
W
CCIF
BLANK
1
0
0
0
0
Reset:
= Unimplemented or Reserved
Figure 3-7 EEPROM Status Register (ESTAT)
CBEIF, PVIOL and ACCERR are readable and writable, CCIF and BLANK are readable and not writable,
remaining bits read zero and are not writable.
CBEIF — Command Buffer Empty Interrupt Flag.
The CBEIF flag indicates that the address, data and command buffers are empty so that a new
command write sequence can be started. The CBEIF flag is cleared by writing a “1” to CBEIF. Writing
a “0” to the CBEIF flag has no effect on CBEIF. Writing a “0” to CBEIF after writing an aligned word
to the EEPROM address space but before CBEIF is cleared will abort a command write sequence and
cause the ACCERR flag to be set. Writing a “0” to CBEIF outside of a command write sequence will
not set the ACCERR flag. The CBEIF flag is used together with the CBEIE bit in the ECNFG register
1 = Buffers are ready to accept a new command.
0 = Buffers are full.
CCIF — Command Complete Interrupt Flag.
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The CCIF flag indicates that there are no more commands pending. The CCIF flag is cleared when
CBEIF is clear and sets automatically upon completion of all active and pending commands. The CCIF
flag does not set when an active commands completes and a pending command is fetched from the
command buffer. Writing to the CCIF flag has no effect on CCIF. The CCIF flag is used together with
1 = All commands are completed.
0 = Command in progress.
PVIOL — Protection Violation Flag.
The PVIOL flag indicates an attempt was made to program or erase an address in a protected area of
the EEPROM memory during a command write sequence. The PVIOL flag is cleared by writing a “1”
to PVIOL. Writing a “0” to the PVIOL flag has no effect on PVIOL. While PVIOL is set, it is not
possible to launch a command or start a command write sequence.
1 = A protection violation has occurred.
0 = No failure.
ACCERR — Access Error Flag.
The ACCERR flag indicates an illegal access has occurred to the EEPROM memory caused by either
(see Table 3-4), launching the sector erase abort command terminating a sector erase operation early
(CCIF=0). The ACCERR flag is cleared by writing a “1” to ACCERR. Writing a “0” to the ACCERR
flag has no effect on ACCERR. While ACCERR is set, it is not possible to launch a command or start
a command write sequence. If ACCERR is set by an erase verify operation, any buffered command
will not launch.
1 = Access error has occurred.
0 = No access error detected.
BLANK — Flag indicating the erase verify operation status.
When the CCIF flag is set after completion of an erase verify command, the BLANK flag indicates the
result of the erase verify operation. The BLANK flag is cleared by the EEPROM module when CBEIF
is cleared as part of a new valid command write sequence. Writing to the BLANK flag has no effect
on BLANK.
1 = EEPROM block verified as erased.
0 = EEPROM block verified as not erased.
3.3.7 ECMD — EEPROM Command Register
The ECMD register is the EEPROM command register.
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Address Offset: $_06
7
0
6
0
5
0
4
0
3
CMDB
0
2
0
1
0
0
0
R
W
0
Reset:
= Unimplemented or Reserved
Figure 3-8 EEPROM Command Register (ECMD)
All CMDB bits are readable and writable during a command write sequence while bit 7 reads zero and is
not writable.
Table 3-4 Valid EEPROM Command List
CMDB[6:0]
$05
Command
Erase Verify
$20
Word Program
Sector Erase
Mass Erase
$40
$41
$47
Sector Erase Abort
Sector Modify
$60
3.3.8 RESERVED3
This register is reserved for factory testing and is not accessible.
Address Offset: $_07
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
0
R
W
0
0
0
0
0
0
0
0
Reset:
= Unimplemented or Reserved
Figure 3-9 RESERVED3
All bits read zero and are not writable.
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3.3.9 EADDR — EEPROM Address Registers
The EADDRHI and EADDRLO registers are the EEPROM address registers.
Address Offset: $_08
7
0
6
0
5
4
3
2
0
1
0
0
R
EABHI
0
0
0
W
0
0
0
0
0
0
Reset:
= Unimplemented or Reserved
Figure 3-10 EEPROM Address High Register (EADDRHI)
Address Offset: $_09
7
6
0
5
0
4
0
3
0
2
0
1
0
0
0
R
W
EABLO
0
Reset:
= Unimplemented or Reserved
Figure 3-11 EEPROM Address Low Register (EADDRLO)
All EABHI and EABLO bits read zero and are not writable in normal modes.
All EABHI and EABLO bits are readable and writable in special modes.
The MCU address bit AB0 is not stored in the EADDR registers since the EEPROM block is not byte
addressable.
3.3.10 EDATA — EEPROM Data Registers
The EDATAHI and EDATALO registers are the EEPROM data registers.
Address Offset: $_0A
7
6
0
5
0
4
0
3
0
2
0
1
0
0
0
R
W
EDHI
0
Reset:
= Unimplemented or Reserved
Figure 3-12 EEPROM Data High Register (EDATAHI)
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Address Offset: $_0B
7
6
0
5
0
4
0
3
0
2
0
1
0
0
0
R
W
EDLO
0
Reset:
= Unimplemented or Reserved
Figure 3-13 EEPROM Data Low Register (EDATALO)
All EDHI and EDLO bits read zero and are not writable in normal modes.
All EDHI and EDLO bits are readable and writable in special modes.
24
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Section 4 Functional Description
4.1 EEPROM Command Operations
Write and read operations are both used for the program, erase, erase verify, sector erase abort, and sector
modify algorithms described in this section. The program, erase, and sector modify algorithms are
controlled by a state machine whose timebase, EECLK, is derived from the oscillator clock via a
programmable divider. The command register as well as the associated address and data registers operate
as a buffer and a register (2-stage FIFO) so that a second command along with the necessary data and
address can be stored to the buffer while the first command is still in progress. Buffer empty as well as
command completion are signalled by flags in the EEPROM status register with interrupts generated, if
enabled.
The next sections describe:
1. How to write the ECLKDIV register.
2. Command write sequences to program, erase, erase verify, sector erase abort, and sector modify
operations on the EEPROM memory.
3. Valid EEPROM commands.
4. Effects resulting from illegal EEPROM command write sequences or aborting EEPROM
operations.
4.1.1 Writing the ECLKDIV Register
Prior to issuing any EEPROM command after a reset, the user is required to write the ECLKDIV register
to divide the oscillator clock down to within the 150kHz to 200kHz range. Since the program and erase
timings are also a function of the bus clock, the ECLKDIV determination must take this information into
account.
If we define:
•
•
•
ECLK as the clock of the EEPROM timing control block,
Tbus as the period of the bus clock,
INT(x) as taking the integer part of x (e.g. INT(4.323)=4),
For example, if the oscillator clock frequency is 950kHz and the bus clock frequency is 10MHz,
ECLKDIV bits EDIV[5:0] should be set to "4" (000100) and bit PRDIV8 set to "0". The resulting EECLK
frequency is then 190kHz. As a result, the EEPROM program and erase algorithm timings are increased
over the optimum target by:
(200 – 190) ⁄ 200 × 100 = 5%
If the oscillator clock frequency is 16MHz and the bus clock frequency is 40MHz, ECLKDIV bits
EDIV[5:0] should be set to "50" (110010) and bit PRDIV8 set to "1". The resulting EECLK frequency is
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then 182kHz. In this case, the EEPROM program and erase algorithm timings are increased over the
optimum target by:
(200 – 182) ⁄ 200 × 100 = 9%
NOTE: "4"Program and erase command execution time will increase proportionally with
the period of EECLK.
NOTE: Because of the impact of clock synchronization on the accuracy of the functional
timings, programming or erasing the EEPROM memory cannot be performed if the
bus clock runs at less than 1 MHz. Programming or erasing the EEPROM memory
with EECLK < 150kHz should be avoided. Setting ECLKDIV to a value such that
EECLK < 150kHz can destroy the EEPROM memory due to overstress. Setting
ECLKDIV to a value such that (1/EECLK+Tbus) < 5µs can result in incomplete
programming or erasure of the EEPROM memory cells.
If the ECLKDIV register is written, the EDIVLD bit is set automatically. If the EDIVLD bit is zero, the
ECLKDIV register has not been written since the last reset. If the ECLKDIV register has not been written
to, the EEPROM command loaded during a command write sequence will not execute and the ACCERR
flag in the ESTAT register will set.
26
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START
no
Tbus < 1µs?
ALL COMMANDS IMPOSSIBLE
yes
PRDIV8=0 (reset)
no
oscillator_clock
12.8MHz?
yes
PRDIV8=1
PRDCLK=oscillator_clock/8
PRDCLK=oscillator_clock
no
PRDCLK[MHz]*(5+Tbus[µs])
an integer?
EDIV[5:0]=INT(PRDCLK[MHz]*(5+Tbus[µs]))
yes
EDIV[5:0]=PRDCLK[MHz]*(5+Tbus[µs])-1
TRY TO DECREASE Tbus
EECLK=(PRDCLK)/(1+EDIV[5:0])
yes
1/EECLK[MHz] + Tbus[µs] > 5
END
AND
EECLK > 0.15MHz
?
no
yes
EDIV[5:0] > 4?
no
ALL COMMANDS IMPOSSIBLE
Figure 4-1 Determination Procedure for PRDIV8 and EDIV Bits
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4.1.2 Command Write Sequence
The EEPROM command controller is used to supervise the command write sequence to execute program,
erase, erase verify, sector erase abort, and sector modify algorithms.
Before starting a command write sequence, the ACCERR and PVIOL flags in the ESTAT register must
be clear (see section 3.3.6) and the CBEIF flag should be tested to determine the state of the address, data
and command buffers. If the CBEIF flag is set, indicating the buffers are empty, a new command write
sequence can be started. If the CBEIF flag is clear, indicating the buffers are not available, a new command
write sequence will overwrite the contents of the address, data and command buffers.
A command write sequence consists of three steps which must be strictly adhered to with writes to the
EEPROM module not permitted between the steps. However, EEPROM register and array reads are
allowed during a command write sequence. The basic command write sequence is as follows:
1. Write to one address in the EEPROM memory.
2. Write a valid command to the ECMD register.
3. Clear the CBEIF flag in the ESTAT register by writing a “1” to CBEIF to launch the command.
The address written in step 1 will be stored in the EADDR registers and the data will be stored in the
EDATA registers. If the CBEIF flag in the ESTAT register is clear when the first EEPROM array write
occurs, the contents of the address and data buffers will be overwritten and the CBEIF flag will be set.
When the CBEIF flag is cleared, the CCIF flag is cleared on the same bus cycle by the EEPROM command
controller indicating that the command was successfully launched. For all command write sequences
except sector erase abort, the CBEIF flag will set four bus cycles after the CCIF flag is cleared indicating
that the address, data, and command buffers are ready for a new command write sequence to begin. For
sector erase abort operations, the CBEIF flag will remain clear until the operation completes. Except for
the sector erase abort command, a buffered command will wait for the active operation to be completed
before being launched. The sector erase abort command is launched when the CBEIF flag is cleared as part
of a sector erase abort command write sequence. Once a command is launched, the completion of the
command operation is indicated by the setting of the CCIF flag in the ESTAT register. The CCIF flag will
set upon completion of all active and buffered commands .
A command write sequence can be aborted prior to clearing the CBEIF flag in the ESTAT register by
writing a “0” to the CBEIF flag and will result in the ACCERR flag in the ESTAT register being set. The
ACCERR flag in the ESTAT register must be cleared prior to starting a new command write sequence.
4.1.3 EEPROM Commands
Table 4-1 summarizes the valid EEPROM commands along with the effects of the commands on the
EEPROM block.
Table 4-1 EEPROM Command Description
ECMDB Command
Function on EEPROM Memory
Verify all memory bytes in the EEPROM block are erased.
If the EEPROM block is erased, the BLANK flag in the ESTAT register will set upon
command completion.
Erase
Verify
$05
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Table 4-1 EEPROM Command Description
ECMDB Command
Function on EEPROM Memory
$20
$40
Program
Program a word (two bytes) in the EEPROM block.
Sector
Erase
Erase all four memory bytes in a sector of the EEPROM block.
Erase all memory bytes in the EEPROM block.
A mass erase of the full EEPROM block is only possible when EPOPEN and EPDIS bits
in the EPROT register are set prior to launching the command.
Mass
Erase
$41
Abort the sector erase operation.
The sector erase operation will terminate according to a set procedure. The EEPROM
sector should not be considered erased if the ACCERR flag is set upon command
completion.
SectorErase
Abort
$47
$60
Sector
Modify
Erase all four memory bytes in a sector of the EEPROM block and reprogram the
addressed word.
NOTE: The user should not program an EEPROM word without first erasing the sector in
which that word resides.
4.1.3.1 Erase Verify Command
The erase verify operation will verify that the EEPROM memory is erased.
An example flow to execute the erase verify operation is shown in Figure 4-2. The erase verify command
write sequence is as follows:
1. Write to an EEPROM address to start the command write sequence for the erase verify command.
The address and data written will be ignored.
2. Write the erase verify command, $05, to the ECMD register.
3. Clear the CBEIF flag in the ESTAT register by writing a “1” to CBEIF to launch the erase verify
command.
After launching the erase verify command, the CCIF flag in the ESTAT register will set after the operation
has completed unless a new command write sequence has been buffered. The number of bus cycles
required to execute the erase verify operation is equal to the number of words in the EEPROM memory
plus 14 bus cycles as measured from the time the CBEIF flag is cleared until the CCIF flag is set. Upon
completion of the erase verify operation, the BLANK flag in the ESTAT register will be set if all addresses
in the EEPROM memory are verified to be erased. If any address in the EEPROM memory is not erased,
the erase verify operation will terminate and the BLANK flag in the ESTAT register will remain clear.
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START
Read: ECLKDIV register
Clock Register
Written
Check
NOTE: ECLKDIV needs to
be set once after each reset.
EDIVLD
Set?
no
yes
Write: ECLKDIV register
Read: ESTAT register
Address, Data,
Command
Buffer Empty Check
CBEIF
Set?
no
yes
ACCERR/
PVIOL
Set?
yes
Access Error and
Protection Violation
Check
Write: ESTAT register
Clear ACCERR/PVIOL $30
no
Write: EEPROM Address
and Dummy Data
1.
2.
3.
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ECMD register
Erase Verify Command $05
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ESTAT register
Clear CBEIF $80
Read: ESTAT register
Bit Polling for
Command Completion
Check
no
no
CCIF
Set?
yes
Erase Verify
Status
BLANK
Set?
yes
EEPROM Memory
Erased
EEPROM Memory
Not Erased
EXIT
EXIT
Figure 4-2 Example Erase Verify Command Flow
4.1.3.2 Program Command
The program operation will program a previously erased word in the EEPROM memory using an
embedded algorithm.
sequence is as follows:
1. Write to an EEPROM block address to start the command write sequence for the program
command. The data written will be programmed to the address written.
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2. Write the program command, $20, to the ECMD register.
3. Clear the CBEIF flag in the ESTAT register by writing a “1” to CBEIF to launch the program
command.
If a word to be programmed is in a protected area of the EEPROM memory, the PVIOL flag in the ESTAT
register will set and the program command will not launch. Once the program command has successfully
launched, the CCIF flag in the ESTAT register will set after the program operation has completed unless
a new command write sequence has been buffered.
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START
Read: ECLKDIV register
Clock Register
Written
Check
NOTE: ECLKDIV needs to
be set once after each reset.
EDIVLD
Set?
no
yes
Write: ECLKDIV register
Read: ESTAT register
Address, Data,
Command
Buffer Empty Check
CBEIF
Set?
no
yes
ACCERR/
PVIOL
Set?
yes
Access Error and
Protection Violation
Check
Write: ESTAT register
Clear ACCERR/PVIOL $30
no
Write: EEPROM Address
and program Data
1.
2.
3.
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ECMD register
Program Command $20
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ESTAT register
Clear CBEIF $80
Read: ESTAT register
Bit Polling for
Buffer Empty
Check
no
CBEIF
Set?
yes
Sequential
Programming
Decision
yes
Next
Word?
no
Read: ESTAT register
Bit Polling for
Command Completion
Check
no
CCIF
Set?
yes
EXIT
Figure 4-3 Example Program Command Flow
4.1.3.3 Sector Erase Command
The sector erase operation will erase both words in a sector of EEPROM memory using an embedded
algorithm.
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An example flow to execute the sector erase operation is shown in Figure 4-4. The sector erase command
write sequence is as follows:
1. Write to an EEPROM memory address to start the command write sequence for the sector erase
command. The EEPROM address written determines the sector to be erased while global address
bits [1:0] and the data written are ignored.
2. Write the sector erase command, $40, to the ECMD register.
3. Clear the CBEIF flag in the ESTAT register by writing a “1” to CBEIF to launch the sector erase
command.
If an EEPROM sector to be erased is in a protected area of the EEPROM memory, the PVIOL flag in the
ESTAT register will set and the sector erase command will not launch. Once the sector erase command
has successfully launched, the CCIF flag in the ESTAT register will set after the sector erase operation has
completed unless a new command write sequence has been buffered.
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START
Read: ECLKDIV register
Clock Register
Written
Check
NOTE: ECLKDIV needs to
be set once after each reset.
EDIVLD
Set?
no
yes
Write: ECLKDIV register
Read: ESTAT register
Address, Data,
Command
Buffer Empty Check
CBEIF
Set?
no
yes
ACCERR/
PVIOL
Set?
yes
Access Error and
Protection Violation
Check
Write: ESTAT register
Clear ACCERR/PVIOL $30
no
Write: EEPROM Sector Address
and Dummy Data
1.
2.
3.
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ECMD register
Sector Erase Command $40
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ESTAT register
Clear CBEIF $80
Read: ESTAT register
Bit Polling for
Command Completion
Check
no
CCIF
Set?
yes
EXIT
Figure 4-4 Example Sector Erase Command Flow
4.1.3.4 Mass Erase Command
The mass erase operation will erase all addresses in an EEPROM block using an embedded algorithm.
write sequence is as follows:
1. Write to an EEPROM memory address to start the command write sequence for the mass erase
command. The address and data written will be ignored.
2. Write the mass erase command, $41, to the ECMD register.
3. Clear the CBEIF flag in the ESTAT register by writing a “1” to CBEIF to launch the mass erase
command.
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If the EEPROM memory to be erased contains any protected area, the PVIOL flag in the ESTAT register
will set and the mass erase command will not launch. Once the mass erase command has successfully
launched, the CCIF flag in the ESTAT register will set after the mass erase operation has completed unless
a new command write sequence has been buffered.
START
Read: ECLKDIV register
Clock Register
Written
Check
NOTE: ECLKDIV needs to
be set once after each reset.
EDIVLD
Set?
no
yes
Write: ECLKDIV register
Read: ESTAT register
Address, Data,
Command
Buffer Empty Check
CBEIF
Set?
no
yes
ACCERR/
PVIOL
Set?
yes
Access Error and
Protection Violation
Check
Write: ESTAT register
Clear ACCERR/PVIOL $30
no
Write: EEPROM Address
and Dummy Data
1.
2.
3.
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ECMD register
Mass Erase Command $41
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ESTAT register
Clear CBEIF $80
Read: ESTAT register
Bit Polling for
Command Completion
Check
no
CCIF
Set?
yes
EXIT
Figure 4-5 Example Mass Erase Command Flow
4.1.3.5 Sector Erase Abort Command
The sector erase abort operation will terminate the active sector erase or sector modify operation so that
other sectors in an EEPROM block are available for read and program operations without waiting for the
sector erase or sector modify operation to complete.
An example flow to execute the sector erase abort operation is shown in Figure 4-6. The sector erase abort
command write sequence is as follows:
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1. Write to any EEPROM memory address to start the command write sequence for the sector erase
abort command. The address and data written are ignored.
2. Write the sector erase abort command, $47, to the ECMD register.
3. Clear the CBEIF flag in the ESTAT register by writing a “1” to CBEIF to launch the sector erase
abort command.
If the sector erase abort command is launched resulting in the early termination of an active sector erase
or sector modify operation, the ACCERR flag will set once the operation completes as indicated by the
CCIF flag being set. The ACCERR flag sets to inform the user that the EEPROM sector may not be fully
erased and a new sector erase or sector modify command must be launched before programming any
location in that specific sector. If the sector erase abort command is launched but the active sector erase or
sector modify operation completes normally, the ACCERR flag will not set upon completion of the
operation as indicated by the CCIF flag being set. If the sector erase abort command is launched after the
sector modify operation has completed the sector erase step, the program step will be allowed to complete.
The maximum number of cycles required to abort a sector erase or sector modify operation is equal to four
cleared until the CCIF flag is set.
NOTE: Since the ACCERR bit in the ESTAT register may be set at the completion of the
sector erase abort operation, a command write sequence is not allowed to be
buffered behind a sector erase abort command write sequence. The CBEIF flag will
not set after launching the sector erase abort command to indicate that a command
should not be buffered behind it. If an attempt is made to start a new command write
sequence with a sector erase abort operation active, the ACCERR flag in the
ESTAT register will be set. A new command write sequence may be started after
clearing the ACCERR flag, if set.
NOTE: The sector erase abort command should be used sparingly since a sector erase
operation that is aborted counts as a complete program/erase cycle.
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Execute Sector Erase/Modify Command Flow
Read: ESTAT register
Erase
Abort
Needed?
Bit Polling for
Command
Completion Check
CCIF
no
no
Set?
yes
yes
Sector Erase
Completed
EXIT
Write: Dummy EEPROM Address
and Dummy Data
1.
2.
3.
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ECMD register
Sector Erase Abort Cmd $47
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ESTAT register
Clear CBEIF $80
Read: ESTAT register
no
Bit Polling for
Command
Completion Check
CCIF
Set?
yes
yes
ACCERR
Set?
Access
Error Check
Write: ESTAT register
Clear ACCERR $10
no
Sector Erase
or Modify
Completed
Sector Erase
or Modify
Aborted
EXIT
EXIT
Figure 4-6 Example Sector Erase Abort Command Flow
4.1.3.6 Sector Modify Command
The sector modify operation will erase both words in a sector of EEPROM memory followed by a
reprogram of the addressed word using an embedded algorithm.
command write sequence is as follows:
1. Write to an EEPROM memory address to start the command write sequence for the sector modify
command. The EEPROM address written determines the sector to be erased and word to be
reprogrammed while byte address bit 0 is ignored.
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2. Write the sector modify command, $60, to the ECMD register.
3. Clear the CBEIF flag in the ESTAT register by writing a “1” to CBEIF to launch the sector erase
command.
If an EEPROM sector to be modified is in a protected area of the EEPROM memory, the PVIOL flag in
the ESTAT register will set and the sector modify command will not launch. Once the sector modify
command has successfully launched, the CCIF flag in the ESTAT register will set after the sector modify
operation has completed unless a new command write sequence has been buffered.
START
Read: ECLKDIV register
Clock Register
Written
Check
NOTE: ECLKDIV needs to
be set once after each reset.
EDIVLD
Set?
no
yes
Write: ECLKDIV register
Read: ESTAT register
Address, Data,
Command
Buffer Empty Check
CBEIF
Set?
no
yes
ACCERR/
PVIOL
Set?
yes
Access Error and
Protection Violation
Check
Write: ESTAT register
Clear ACCERR/PVIOL $30
no
Write: EEPROM Word Address
and program Data
1.
2.
3.
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ECMD register
Sector Modify Command $60
NOTE: command write sequence
aborted by writing $00 to
ESTAT register.
Write: ESTAT register
Clear CBEIF $80
Read: ESTAT register
Bit Polling for
Command Completion
Check
no
CCIF
Set?
yes
EXIT
Figure 4-7 Example Sector Modify Command Flow
4.1.4 Illegal EEPROM Operations
The ACCERR flag will be set during the command write sequence if any of the following illegal steps are
performed, causing the command write sequence to immediately abort:
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1. Writing to an EEPROM address before initializing the ECLKDIV register.
2. Writing a byte or misaligned word to a valid EEPROM address.
3. Starting a command write sequence while a sector erase abort operation is active.
4. Writing to any EEPROM register other than ECMD after writing to an EEPROM address.
5. Writing a second command to the ECMD register in the same command write sequence.
6. Writing an invalid command to the ECMD register.
7. Writing to an EEPROM address after writing to the ECMD register.
8. Writing to any EEPROM register other than ESTAT (to clear CBEIF) after writing to the ECMD
register.
9. Writing a “0” to the CBEIF flag in the ESTAT register to abort a command write sequence.
The ACCERR flag will not be set if any EEPROM register is read during a valid command write sequence.
The ACCERR flag will also be set if any of the following events occur:
1. Launching the sector erase abort command while a sector erase or sector modify operation is active
which results in the early termination of the sector erase or sector modify operation (see section
4.1.3.5).
2. The MCU enters STOP mode and a command operation is in progress. The operation is aborted
If the EEPROM memory is read during execution of an algorithm (CCIF = 0), the read operation will
return invalid data and the ACCERR flag will not be set.
If the ACCERR flag is set in the ESTAT register, the user must clear the ACCERR flag before starting
The PVIOL flag will be set after the command is written to the ECMD register during a command write
sequence if any of the following illegal operations are attempted, causing the command write sequence to
immediately abort:
1. Writing the program command if the address written in the command write sequence was in a
protected area of the EEPROM memory.
2. Writing the sector erase command if the address written in the command write sequence was in a
protected area of the EEPROM memory.
3. Writing the mass erase command to the EEPROM memory while any EEPROM protection is
enabled.
4. Writing the sector modify command if the address written in the command write sequence was in
a protected area of the EEPROM memory.
If the PVIOL flag is set in the ESTAT register, the user must clear the PVIOL flag before starting another
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4.2 Wait Mode
If a command is active (CCIF=0) when the MCU enters the WAIT mode, the active command and any
buffered command will be completed.
The EEPROM module can recover the MCU from WAIT if the CBEIF and CCIF interrupts are enabled
4.3 Stop Mode
If a command is active (CCIF = 0) when the MCU enters the STOP mode, the operation will be aborted
and, if the operation is program, sector erase, mass erase, or sector modify, the EEPROM array data being
programmed or erased may be corrupted and the CCIF and ACCERR flags will be set. If active, the high
voltage circuitry to the EEPROM memory will immediately be switched off when entering STOP mode.
Upon exit from STOP, the CBEIF flag is set and any buffered command will not be launched. The
NOTE: As active commands are immediately aborted when the MCU enters STOP mode, it
is strongly recommended that the user does not use the STOP command during
program, sector erase, mass erase, or sector modify operations.
4.4 Background Debug Mode
In background debug mode (BDM), the EPROT register is writable. If the MCU is unsecured, then all
chip mode, the only command available to execute is mass erase.
4.5 EEPROM Module Security
The EEPROM module does not provide any security information to the MCU. After each reset, the
security state of the MCU is a function of information provided by the Flash module (see the specific FTX
Block Guide).
4.5.1 Unsecuring the MCU in Special Single Chip Mode via the BDM
Before the MCU can be unsecured in special single chip mode, the EEPROM memory must be erased
using the following method:
•
Reset the MCU into special single chip mode, delay while the erase test is performed by the BDM
secure ROM, send BDM commands to disable protection in the EEPROM module, and execute a
mass erase command write sequence to erase the EEPROM memory.
After the CCIF flag sets to indicate that the EEPROM mass operation has completed and assuming that
the Flash memory has also been erased, reset the MCU into special single chip mode. The BDM secure
ROM will verify that the Flash and EEPROM memory are erased and will assert the UNSEC bit in the
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BDM status register. This BDM action will cause the MCU to override the Flash security state and the
MCU will be unsecured. Once the MCU is unsecured, BDM commands will be enabled and the Flash
security byte may be programmed to the unsecure state.
4.6 Resets
4.6.1 EEPROM Reset Sequence
On each reset, the EEPROM module executes a reset sequence to hold CPU activity while loading the
4.6.2 Reset While EEPROM Command Active
If a reset occurs while any EEPROM command is in progress, that command will be immediately aborted.
The state of a word being programmed or the sector / block being erased is not guaranteed.
4.7 Interrupts
The EEPROM module can generate an interrupt when all EEPROM command operations have completed,
when the EEPROM address, data and command buffers are empty.
Table 4-2 EEPROM Interrupt Sources
Global (CCR)
Interrupt Source
Interrupt Flag
Local Enable
Mask
EEPROM Address, Data and
Command Buffers empty
CBEIF
(ESTAT register)
CBEIE
(ECNFG register)
I-Bit
CCIF
(ESTAT register)
CCIE
(ECNFG register)
All EEPROM commands completed
I-Bit
Vector addresses and their relative interrupt priority are determined at the MCU level.
4.7.1 Description of EEPROM Interrupt Operation
The EEPROM module uses the CBEIF and CCIF flags in combination with the CBIE and CCIE enable
bits to generate the EEPROM command interrupt request.
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CBEIF
CBEIE
EEPROM Command Interrupt Request
CCIF
CCIE
Figure 4-8 EEPROM Interrupt Implementation
For a detailed description of the register bits, refer to the EEPROM Configuration register and EEPROM
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–S–
Index
–W–
–A–
–B–
–C–
–E–
–I–
–K–
–P–
–R–
Registers
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Block Guide End Sheet
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FINAL PAGE OF
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