SAM7X256_14 Datasheet, PDF (103/662 Pages) ATMEL Corporation – ARM-based Flash MCU

All the commands are protected by the same keyword, which has to be written in the eight highest bits of the MC_FCR
register.
Writing MC_FCR with data that does not contain the correct key and/or with an invalid command has no effect on the
memory plane; however, the PROGE flag is set in the MC_FSR register. This flag is automatically cleared by a read
access to the MC_FSR register.
When the current command writes or erases a page in a locked region, the command has no effect on the whole memory
plane; however, the LOCKE flag is set in the MC_FSR register. This flag is automatically cleared by a read access to the
MC_FSR register.
Figure 19-5. Command State Chart
Read Status: MC_FSR
No
Check if FRDY flag set
Yes
Write FCMD and PAGENB in MC_FCR
Read Status: MC_FSR
No
Check if FRDY flag set
Yes
Yes
Check if LOCKE flag set
Locking region violation
No
Yes
Check if PROGE flag set
Bad keyword violation and/or Invalid command
No
Command Successful
In order to guarantee valid operations on the Flash memory, the field Flash Microsecond Cycle Number (FMCN) in the
Flash Mode Register MC_FMR must be correctly programmed (see “MC Flash Mode Register” on page 108).
19.2.4.1 Flash Programming
Several commands can be used to program the Flash.
SAM7X Series [DATASHEET]
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