355
SAM4CP [DATASHEET]
43051E–ATPL–08/14
In order to perform one of these commands, select the desired command using the FCMD field in the Flash Command
register (EEFC_FCR). As soon as EEFC_FCR is written, the FRDY flag and the FVALUE field in the Flash Result
register (EEFC_FRR) are automatically cleared. Once the current command has completed, the FRDY flag is
automatically set. If an interrupt has been enabled by setting the bit EEFC_FMR.FRDY, the corresponding interrupt line
of the interrupt controller is activated. (Note that this is true for all commands except for the STUI Command. The FRDY
flag is not set when the STUI command has completed).
All the commands are protected by the same keyword, which must be written in the eight highest bits of EEFC_FCR.
Writing EEFC_FCR with data that does not contain the correct key and/or with an invalid command has no effect on the
whole memory plane, but the FCMDE flag is set in the Flash Status register (EEFC_FSR). This flag is automatically
cleared by a read access to EEFC_FSR.
When the current command writes or erases a page in a locked region, the command has no effect on the whole memory
plane, but the FLOCKE flag is set in EEFC_FSR. This flag is automatically cleared by a read access to EEFC_FSR.
Erase Sector
0x11
ES
Write User Signature
0x12
WUS
Erase User Signature
0x13
EUS
Start Read User Signature
0x14
STUS
Stop Read User Signature
0x15
SPUS
Table 22-2.
Set of Commands (Continued)
Command
Value
Mnemonic