T89C51AC2-RLSI-M datasheet(43/117 Pages) ATMEL

tên linh kiện	T89C51AC2-RLSI-M

Giải thích chi tiết về linh kiện	8-bit MCU with 32K bytes Flash, 10 bits A/D and EEPROM

PDF	117 Pages

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nhà sản xuất	ATMEL [ATMEL Corporation]

Trang chủ	http://www.atmel.com

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43 / 117 page

Draft.A - March 30, 2001

Preview - Confidential

T89C51AC2

10.2.1. Flash Parallel Programming

The three lock bits in Hardware byte are programmed according to Table, will provide different level of protection

for the on-chip code and data located in FM0 and FM1.

The only way for write this bits are the parallel mode.

Table 17. Program Lock bit

Program Lock bits

U: unprogrammed

P: programmed

WARNING: Security level 2 and 3 should only be programmed after Flash and Core verification.

Program Lock bits

These security bits protect the code access through the parallel programming interface. They are set by default to

level 4.

Program Lock Bits

Protection description

Security

level

LB0

LB1

LB2

UUU

No program lock features enabled. MOVC instruction executed from external program

memory returns non encrypted data.

MOVC instruction executed from external program memory are disabled from fetching

code bytes from internal memory, EA is sampled and latched on reset, and further

parallel programming of the Flash is disabled.

Same as 2, also verify through parallel programming interface is disabled.

Same as 3, also external execution is disabled.

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