Information

28.3.2.1 Program Once Field
The Program Once Field in the program flash IFR provides 64 bytes of user data storage
separate from the program flash main array. The user can program the Program Once
Field one time only as there is no program flash IFR erase mechanism available to the
user. The Program Once Field can be read any number of times. This section of the
program flash IFR is accessed in 4-Byte records using the Read Once and Program Once
commands (see Read Once Command and Program Once Command).
28.3.3 Data Flash IFR Map
The data flash IFR is a 256 byte nonvolatile information memory that can be read and
erased, but the user has limited program capabilities in the data flash IFR (see the
Program Partition command in Program Partition Command, the Erase All Blocks
command in Erase All Blocks Command, and the Read Resource command in Read
Resource Command). The contents of the data flash IFR are summarized in the following
table and further described in the subsequent paragraphs.
Address Range Size (Bytes) Field Description
0x00 – 0xFB, 0xFE – 0xFF 254 Reserved
0xFD 1 EEPROM data set size
0xFC 1 FlexNVM partition code
28.3.3.1 EEPROM Data Set Size
The EEPROM data set size byte in the data flash IFR supplies information which
determines the amount of FlexRAM used in each of the available EEPROM subsystems.
To program the EEESIZE value, see the Program Partition command described in
Program Partition Command.
Table 28-1. EEPROM Data Set Size
Data flash IFR: 0x00FD
7 6 5 4 3 2 1 0
1 1 1 1 EEESIZE
= Unimplemented or Reserved
Memory Map and Registers
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
504 Freescale Semiconductor, Inc.