ColdFire Flash Module (CFM)
MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor 18-21
Page Erase Verify
The page erase verify operation verifies all memory addresses in a flash logical page are erased.
An example flow to execute the page erase verify operation is shown in Figure 18-15. The page erase
verify command write sequence is as follows:
1. W rite to any word address in a flash logical page to star t the command write sequence for the page
erase verify command. The address written determines the flash logical page to be verified, while
the data written during the page erase verify command write sequence is ignored.
2. Write the page erase verify command, $06, to the CFMCMD register.
3. Clear the CBEIF flag by writing a 1 to CBEIF to launch the page erase verify command.
Because the word addresses in even and odd flash blocks are interleaved, pages from adjacent interleaving
flash physical blocks are automatically erase verified at the same time. The number of internal flash bus
cycles required to execute the page erase verify operation on a fully erased flash logical page is equal to
the number of word addresses in a flash logical page plus 15 internal flash bus cycles as measured from
the time the CBEIF flag is cleared until the CCIF flag is set in the CFMUSTAT register.
Upon completion of any page erase verify operation (CCIF=1), the BLANK flag in the CFMUSTAT
register is set if all addresses in the selected flash logical page are verified to be erased. If any address in
the selected flash logical page is not erased, the page erase verify operation terminates and the BLANK
flag remains clear.