C8051T627-B-GM Silicon Labs, C8051T627-B-GM Datasheet - Page 116

• Manufacturer Part Number: C8051T627-B-GM
• Description: 8-bit Microcontrollers - MCU UBS, 64K OTP MCU
• Manufacturer: Silicon Labs

Specifications of C8051T627-B-GM

• Rohs: yes
• Core: 8051
• Processor Series: C8051T627
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 48 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 3328 B
• On-chip Adc: Yes
• Operating Supply Voltage: 1.8 V to 5.25 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: QFN-32
• Mounting Style: SMD/SMT
• Program Memory Type: EPROM

C8051T620/1/6/7 & C8051T320/1/2/3
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
116
Name
Reset
Name
Reset
7:1
7:0 MEMKEY[7:0] EPROM Lock and Key Register.
Bit
Bit
Type
Type
0
Bit
Bit
Unused
PSWE
Name
Name
R
7
0
7
0
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
Rev. 1.2
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