22.4.3 Flash Commands

The EEFC offers a set of commands to manage programming the Flash memory, locking and unlocking lock regions, consecutive programming, locking and full Flash erasing, and so on.

The commands are listed in the following table.

Table 22-1. Set of Commands
Command Value Mnemonic
Get Flash Descriptor 0x00 GETD
Write Page 0x01 WP
Write Page and Lock 0x02 WPL
Erase Page and Write Page 0x03 EWP
Erase Page and Write Page and then Lock 0x04 EWPL
Erase All 0x05 EA
Erase Pages 0x07 EPA
Set Lock Bit 0x08 SLB
Clear Lock Bit 0x09 CLB
Get Lock Bit 0x0A GLB
Set GPNVM Bit 0x0B SGPB
Clear GPNVM Bit 0x0C CGPB
Get GPNVM Bit 0x0D GGPB
Start Read Unique Identifier 0x0E STUI
Stop Read Unique Identifier 0x0F SPUI
Get CALIB Bit 0x10 GCALB
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

To execute one of these commands, select the required 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 (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.

Figure 22-7. Command State Chart