C8051T322-GQR Silicon Labs, C8051T322-GQR Datasheet - Page 111

• Manufacturer Part Number: C8051T322-GQR
• Description: 8-bit Microcontrollers - MCU USB-OTP-16K-LQFP32
• Manufacturer: Silicon Labs

Specifications of C8051T322-GQR

• Rohs: yes
• Core: 8051
• Processor Series: C8051
• Data Bus Width: 8 bit

SFR Definition 18.1. PSCTL: Program Store R/W Control
SFR Address = 0x8F
SFR Definition 18.2. MEMKEY: EPROM Memory Lock and Key
SFR Address = 0xB7
Name
Reset
Name
Reset
Bit
7:1
Bit
7:0 MEMKEY[7:0] EPROM Lock and Key Register.
Type
Type
0
Bit
Bit
Unused
PSWE
Name
Name
R
7
0
7
0
Unused. Read = 0000000b. Write = don’t care.
Program Store Write Enable.
Setting this bit allows writing a byte of data to the EPROM program memory using the
MOVX write instruction.
0: Writes to EPROM program memory disabled.
1: Writes to EPROM program memory enabled; the MOVX write instruction targets
EPROM memory.
Write:
This register provides a lock and key function for EPROM writes. EPROM writes are
enabled by writing 0xA5 followed by 0xF1 to the MEMKEY register. EPROM writes
are automatically disabled after the next write is complete. If any writes to MEMKEY
are performed incorrectly, or if a EPROM write operation is attempted while these
operations are disabled, the EPROM will be permanently locked from writes until the
next device reset. If an application never writes to EPROM, it can intentionally lock
the EPROM by writing a non-0xA5 value to MEMKEY from software.
Read:
When read, bits 1–0 indicate the current EPROM lock state.
00: EPROM is write locked.
01: The first key code has been written (0xA5).
10: EPROM is unlocked (writes allowed).
11: EPROM writes disabled until the next reset.
R
6
0
6
0
R
5
0
5
0
C8051T620/621/320/321/322/323
Rev. 1.1
MEMKEY[7:0]
R
4
0
4
0
R/W
Function
Function
R
3
0
3
0
R
2
0
2
0
R
1
0
1
0
PSWE
R/W
0
0
0
0
111