RM0440 Rev 4 215/2126
RM0440 Embedded Flash memory (FLASH) for category 2 devices
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5.7.2 Flash Power-down key register (FLASH_PDKEYR)
Address offset: 0x04
Reset value: 0x0000 0000
Access: no wait state, word access
Bit 11 ICRST: Instruction cache reset
0: Instruction cache is not reset
1: Instruction cache is reset
This bit can be written only when the instruction cache is disabled.
Bit 10 DCEN: Data cache enable
0: Data cache is disabled
1: Data cache is enabled
Bit 9 ICEN: Instruction cache enable
0: Instruction cache is disabled
1: Instruction cache is enabled
Bit 8 PRFTEN: Prefetch enable
0: Prefetch disabled
1: Prefetch enabled
Bits 7:4 Reserved, must be kept at reset value.
Bits 3:0 LATENCY[3:0]: Latency
These bits represent the ratio of the SYSCLK (system clock) period to the Flash
access time.
0000: Zero wait state
0001: One wait state
0010: Two wait states
0011: Three wait states
0100: Four wait states
...1111: Fifteen wait states
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
PDKEYR[31:16]
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15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
PDKEYR[15:0]
wwwwwww wwwwwwwww
Bits 31:0 PDKEYR: Power-down in Run mode Flash key
The following values must be written consecutively to unlock the RUN_PD bit in
FLASH_ACR:
PDKEY1: 0x0415 2637
PDKEY2: 0xFAFB FCFD