Sfr Definition 12.1. Psctl: Program Store R/W Control; Sfr Definition 12.2. Flkey: Flash Lock And Key - Silicon Laboratories C8051F341 Product Manual

C8051F340/1/2/3/4/5/6/7/8/9/A/B/C/D

SFR Definition 12.1. PSCTL: Program Store R/W Control

R/W R/W
- -
Bit7 Bit6
Bits7–3: Unused: Read = 00000b. Write = don't care.
Bit2: Reserved. Read = 0b. Must Write = 0b.
Bit1: PSEE: Program Store Erase Enable
Setting this bit (in combination with PSWE) allows an entire page of Flash program memory
to be erased. If this bit is logic 1 and Flash writes are enabled (PSWE is logic 1), a write to
Flash memory using the MOVX instruction will erase the entire page that contains the loca-
tion addressed by the MOVX instruction. The value of the data byte written does not matter.
0: Flash program memory erasure disabled.
1: Flash program memory erasure enabled.
Bit0: PSWE: Program Store Write Enable
Setting this bit allows writing a byte of data to the Flash program memory using the MOVX
write instruction. The Flash location should be erased before writing data.
0: Writes to Flash program memory disabled.
1: Writes to Flash program memory enabled; the MOVX write instruction targets Flash
memory.

SFR Definition 12.2. FLKEY: Flash Lock and Key

R/W R/W
Bit7 Bit6
Bits–0: FLKEY: Flash Lock and Key Register
Write:
This register must be written to before Flash writes or erases can be performed. Flash
remains locked until this register is written to with the following key codes: 0xA5, 0xF1. The
timing of the writes does not matter, as long as the codes are written in order. The key codes
must be written for each Flash write or erase operation. Flash will be locked until the next
system reset if the wrong codes are written or if a Flash operation is attempted before the
codes have been written correctly.
Read:
When read, bits 1-0 indicate the current Flash lock state.
00: Flash is write/erase locked.
01: The first key code has been written (0xA5).
10: Flash is unlocked (writes/erases allowed).
11: Flash writes/erases disabled until the next reset.
112
R/W R/W R/W
- - -
Bit5 Bit4 Bit3
R/W R/W R/W
Bit5 Bit4 Bit3
Rev. 1.3
R/W R/W
Reserved PSEE PSWE
Bit2 Bit1
R/W R/W
Bit2 Bit1
R/W Reset Value
00000000
Bit0 SFR Address:
0x8F
R/W Reset Value
00000000
Bit0 SFR Address:
0xB7