
Functional Description and Application Information
32 kbyte Flash Module (S12SFTSR32KV1)
MM912F634
Freescale Semiconductor
286
A command write sequence consists of three steps which must be strictly adhered to with writes to the Flash module
not permitted between the steps. However, Flash register and array reads are allowed during a command write
sequence. The basic command write sequence is as follows:
1.
Write to a valid address in the Flash array memory.
2.
Write a valid command to the FCMD register.
3.
Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the command.
Once a command is launched, the completion of the command operation is indicated by the setting of the CCIF flag in the FSTAT
register with an interrupt generated, if enabled. The CCIF flag will set upon completion of all active and buffered burst program
commands.
4.36.4.2
Flash Commands
CAUTION
A Flash block address must be in the erased state before being programmed. Cumulative
programming of bits within a Flash block address is not allowed except for the status field
updates required in EEPROM emulation applications.
Table 385 summarizes the valid Flash commands along with the effects of the commands on the Flash block.
Table 385. Flash Command Description
FCMDB
NVM
Command
Function on Flash Memory
0x05
Erase Verify
Verify all memory bytes in the Flash array memory are erased. If the Flash array memory is erased,
the BLANK flag in the FSTAT register will set upon command completion.
0x20
Program
Program an address in the Flash array.
0x25
Burst Program
Program an address in the Flash array with the internal address incrementing after the program
operation.
0x40
Sector Erase
Erase all memory bytes in a sector of the Flash array.
0x41
Mass Erase
Erase all memory bytes in the Flash array. A mass erase of the full Flash array is only possible when
no protection is enabled prior to launching the command.
0x75
Set Verify Margin
Level
Set sense-amp margin levels for verifying Flash array contents (special mode only).