Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
24
/
631
Bit field
Name
Description
0
:
FLASH not working in sleep mode;
1
:
FLASH working in sleep mode.
9
LVMEN
FLASH low-voltage working mode enable
0: Turn off FLASH low-voltage working mode;
1: Enable FLASH low-voltage working mode.
Note: FLASH_AC.LATENCY must be greater than 0x02 to enable FLASH low
voltage operation mode.
8
LVMF
FLASH low voltage working mode flag
0: FLASH is not working in low voltage working mode;
1: FLASH works in low voltage working mode.
7
ICAHEN
iCache enable
0: Turn off iCache;
1: Enable iCache.
6
ICAHRST
iCache reset
0: Writing '0' is invalid;
1: Write '1' to reset.
5
PRFTBFS
Prefetch buffer status
This bit indicates the status of the prefetch buffer
0: The prefetch buffer is closed;
1: The prefetch buffer is open.
4
PRFTBFE
Prefetch buffer enable
0: Close the prefetch buffer;
1: Enable prefetch buffer.
3
Reserved
Reserved, the reset value must be maintained.
2:0
LATENCY
time delay
These bits represent the ratio of SYSCLK (system clock) period to flash memory
access time.
000: Zero period delay, when 0 < SYSCLK <=32MHz
001: One cycle delay, when 32MHz < SYSCLK <=64MHz
010: Two cycle delay, when 64MHz < SYSCLK <=96MHz
011: Three cycle delay, when 96MHz < SYSCLK <= 108MHz
Other values: reserved
2.2.4.2.2
The FLASH key register (FLASH_KEY)
Address offset: 0x04
Reset value: 0xXXXX XXXX