Freescale Semiconductor ColdFire MCF52210 - Manual (Page 309)

ColdFire Flash Module (CFM)
MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor 18-19
buffered command waits for the active command to be completed before being launched. The CCIF flag
in the CFMUSTAT register set upon completion of all active and buffered commands.
A command write sequence can be aborted at anytime prior to clearing the CBEIF flag in the CFMUSTAT
register by writing a 0 to the CBEIF flag. The ACCERR flag in the CFMUSTAT register is set after
successfully aborting a command write sequence and the ACCERR flag must be cleared prior to starting
a new command write sequence.
18.4.2.3.3 Bus Arbitration During Write Operations
After a command has been successfully launched, the CFM signals the core platform to hold off read
accesses to any active flash physical block until all active and buffered commands have completed
(CCIF=1). A flash write operation from the internal flash bus holds off the Core platform until it is
completed.
18.4.2.3.4 Flash Normal Mode Commands
Table 18-16 summarizes the valid flash normal mode commands.
Blank Check
The blank check operation verifies all flash memory addresses in the CFM are erased.
An example flow to execute the blank check command is shown in Figure 18-14 . The blank check
command write sequence is as follows:
1. Write to any flash memory address to start the command write sequence for the blank check
command. The specific address and data written during the blank check command write sequence
is ignored.
2. Write the blank check command, $05, to the CFMCMD register.
3. Clear the CBEIF flag by writing a 1 to CBEIF to launch the blank check command.
Because all flash physical blocks are verified simultaneously, the number of internal flash bus cycles
required to execute the blank check operation on a fully erased flash memory is equal to the number of
word addresses in a flash logical block 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 the blank
Table 18-16. CFM Flash Memory Command Description
CFMCMD Meaning Description
$05 Blank Check Verify that the entire flash memory is erased. If all bits are erased, the BLANK bit sets in
the CFMUSTAT register,
Figure 18-11 , upon command completion.
$06 Page Erase
Verify
Verifies that a flash logical page is erased. If the flash logical page is erased, the BLANK
bit sets in the CFMUSTAT register,
Figure 18-11 , upon command completion.
0x20 Program Program a 32-bit word.
$40 Page Erase Erase a flash logical page.
$41 Mass Erase Erase the entire flash memory. All flash memory protection must be disabled.