45.3.2.1 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
).
45.3.3 Register Descriptions
The flash memory module contains a set of memory-mapped control and status registers.
The FCCOB register group uses a big endian addressing convention. These registers can
be accessed as individual bytes, aligned 16-bit half-words or aligned 32-bit words. While
accessing these registers as half-words or words in a little endian system, ensure that the
correct order of the individual FCCOB registers is achieved.
NOTE
While a command is running (FSTAT[CCIF]=0), register
writes are not accepted to any register except FCNFG and
FSTAT. The no-write rule is relaxed during the start-up reset
sequence, prior to the initial rise of CCIF. During this
initialization period the user may write any register. All register
writes are also disabled (except for registers FCNFG and
FSTAT) whenever an erase suspend request is active
(FCNFG[ERSSUSP]=1).
FTFA memory map
Absolute
address
(hex)
Register name
Width
(in bits)
Access Reset value
Section/
page
4002_0000 Flash Status Register (FTFA_FSTAT)
8
R/W
00h
4002_0001 Flash Configuration Register (FTFA_FCNFG)
8
R/W
00h
4002_0002 Flash Security Register (FTFA_FSEC)
8
R
Undefined
4002_0003 Flash Option Register (FTFA_FOPT)
8
R
Undefined
4002_0004
Flash Common Command Object Registers
(FTFA_FCCOB3)
8
R/W
00h
Table continues on the next page...
Memory Map and Registers
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
892
Freescale Semiconductor, Inc.
