27.4.10 Flash Command Description
This section describes all flash commands that can be launched by a command write
sequence. The flash memory module sets the FSTAT[ACCERR] bit and aborts the
command execution if any of the following illegal conditions occur:
• There is an unrecognized command code in the FCCOB FCMD field.
• There is an error in a FCCOB field for the specific commands. Refer to the error
handling table provided for each command.
Ensure that the ACCERR and FPVIOL bits in the FSTAT register are cleared prior to
starting the command write sequence. As described in Launch the Command by Clearing
CCIF, a new command cannot be launched while these error flags are set.
Do not attempt to read a flash block while the flash memory module is running a
command (CCIF = 0) on that same block. The flash memory module may return invalid
data to the MCU with the collision error flag (FSTAT[RDCOLERR]) set.
CAUTION
Flash data must be in the erased state before being
programmed. Cumulative programming of bits (adding more
zeros) is not allowed.
27.4.10.1 Read 1s Section Command
The Read 1s Section command checks if a section of program flash memory is erased to
the specified read margin level. The Read 1s Section command defines the starting
address and the number of longwords to be verified.
Table 27-26. Read 1s Section Command FCCOB Requirements
FCCOB Number FCCOB Contents [7:0]
0 0x01 (RD1SEC)
1 Flash address [23:16] of the first longword to be verified
2 Flash address [15:8] of the first longword to be verified
3 Flash address [7:0]
1
of the first longword to be verified
4 Number of longwords to be verified [15:8]
5 Number of longwords to be verified [7:0]
6 Read-1 Margin Choice
1. Must be longword aligned (Flash address [1:0] = 00).
Chapter 27 Flash Memory Module (FTFA)
KL25 Sub-Family Reference Manual, Rev. 3, September 2012
Freescale Semiconductor, Inc. 441
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