Motorola ColdFire MCF5281 - Manual (Page 131)

ColdFire Flash Module (CFM)
Freescale Semiconductor 6-19
NOTE
The page erase command operates simultaneously on adjacent erase pages
in two interleaved Flash physical blocks. Thus, a single erase page is
effectively 2 Kbyte.
2. Write the program, erase, or verify command to CFMCMD, the command buffer. See
Section 6.4.3.3, “Flash Valid Commands .”
3. Launch the command by writing a 1 to the CBEIF flag. This clears CBEIF. When command
execution is complete, the Flash state machine sets the CCIF flag. The CBEIF flag is also set
again, indicating that the address, data, and command buffers are ready for a new command
sequence to begin.
The Flash state machine flags errors in command write sequences by means of the ACCERR and PVIOL
flags in the CFMUSTAT register. An erroneous command write sequence self-aborts and sets the
appropriate flag. The ACCERR or PVIOL flags must be cleared before commencing another command
write sequence.
NOTE
By writing a 0 to CBEIF, a command sequence can be aborted after the
longword write to the CFM array or the command write to the CFMCMD
and before the command is launched. The ACCERR flag will be set on
aborted commands and must be cleared before a new command write
sequence.
A summary of the programming algorithm is shown in Figure 6-13 . The flow is similar for the erase and
verify algorithms with the exceptions noted in step 1 above.
6.4.3.3 Flash Valid Commands
Table 6-13 summarizes the valid Flash user commands.
Table 6-13. Flash User Commands
CFMCMD Meaning Description
0x05 Erase
verify
Verify that all 256 Kbytes of Flash from two interleaving physical
blocks are erased. If both blocks are erased, the BLANK bit will
be set in the CFMUSTAT register upon command completion.
0x20 Program Program a 32-bit longword.
0x40 Page
erase
Erase 2 Kbyte of Flash. Two 1024-byte pages from interleaving
physical blocks are erased in this operation.
0x41 Mass
erase
Erase all 256 Kbytes of Flash from two interleaving physical
blocks. A mass erase is only possible when no PROTECT bits
are set for that block.
0x06 Page erase
verify
Verify that the two 1024-byte pages are erased. If both pages
are erased, the BLANK bit will be set in the CFMUSTAT register
upon command completion.
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3