at89c51cc02ua-tdsum ATMEL Corporation, at89c51cc02ua-tdsum Datasheet - Page 50

• Manufacturer Part Number: at89c51cc02ua-tdsum
• Description: At89c51cc02, T89c51cc02 Enhanced 8-bit Microcontroller With Can Controller And Flash
• Manufacturer: ATMEL Corporation

Hardware Security Byte
50
AT/T89C51CC02
Table 32. Hardware Security byte
After erasing the chip in parallel mode, the default value is : FFh
The erasing in ISP mode (from bootloader) does not modify this byte.
Notes:
Number
X2B
5 - 3
2 - 0
Bit
7
7
6
1. Only the 4 MSB bits can be accessed by software.
2. The 4 LSB bits can only be accessed by parallel mode.
Mnemonic Description
BLJB
LB2:0
BLJB
X2B
Bit
6
-
X2 bit
Set this bit to start in standard mode
Clear this bit to start in X2 Mode.
Boot Loader Jump bit
- 1: To start the user’s application on next RESET (@0000h) located in FM0,
- 0: To start the boot loader(@F800h) located in FM1.
Reserved
The value read from these bits are indeterminate.
Lock bits (see Table 22)
5
-
4
-
3
-
LB2
2
LB1
1
4126L–CAN–01/08
LB0
0