AT91SAM7S32-AI ATMEL [ATMEL Corporation], AT91SAM7S32-AI Datasheet - Page 93

• Manufacturer Part Number: AT91SAM7S32-AI
• Description: AT91 ARM Thumb-based Microcontrollers
• Manufacturer: ATMEL [ATMEL Corporation]

Write Operations
Flash Commands
6071A–ATARM–28-Oct-04
The internal memory area reserved for the embedded Flash can also be written through a
write-only latch buffer. Write operations take into account only the 8 lowest address bits and
thus wrap around within the internal memory area address space and appear to be repeated
1024 times within it.
Write operations can be prevented by programming the Memory Protection Unit of the
product.
Writing 8-bit and 16-bit data is not allowed and may lead to unpredictable data
corruption.
Write operations are performed in the number of wait states equal to the number of wait states
for read operations + 1, except for FWS = 3 (see “MC Flash Mode Register” on page 99).
The Embedded Flash Controller offers a command set to manage programming the memory
flash, locking and unlocking lock sectors, consecutive programming and locking, and full Flash
erasing.
Table 17. Set of Commands
To run one of these commands, the field FCMD of the MC_FCR register has to be written with
the command number. As soon as the MC_FCR register is written, the FRDY flag is automati-
cally cleared. Once the current command is achieved, then the FRDY flag is automatically set.
If an interrupt has been enabled by setting the bit FRDY in MC_FMR, the interrupt line of the
Memory Controller is activated.
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 com-
mand 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 FLOCKE flag is set in the MC_FSR register.
This flag is automatically cleared by a read access to the MC_FSR register.
Command
Write page
Set Lock Bit
Write Page and Lock
Clear Lock Bit
Erase all
Set General-purpose NVM Bit
Clear General-purpose NVM Bit
Set Security Bit
AT91SAM7S32 Preliminary
Value
0x0D
0x0B
0x0F
0x01
0x02
0x03
0x04
0x08
Mnemonic
SGPB
CGPB
WPL
CLB
SSB
SLB
WP
EA
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