AT89C51IC2-RLTIM ATMEL [ATMEL Corporation], AT89C51IC2-RLTIM Datasheet - Page 111

• Manufacturer Part Number: AT89C51IC2-RLTIM
• Description: 8-bit Flash Microcontroller with 2-wire Interface
• Manufacturer: ATMEL [ATMEL Corporation]

Flash Memory Status
Figure 42. Flash Memory Possible Contents
Memory Organization
4301C–8051–06/06
0000h
7FFFh
Default
Virgin
Table 88. Program Lock Bits of the SSB
Note:
AT89C51IC2 parts are delivered in standard with the ISP boot in the Flash memory.
After ISP or parallel programming, the possible contents of the Flash memory are sum-
marized on Figure 42.
In the AT89C51IC2, the lowest 32K of the 64 KB program memory address space is
filled by internal Flash.
When the EA pin is high, the processor fetches instructions from internal program Flash.
Bus expansion for accessing program memory from 32K upward automatic since exter-
nal instruction fetches occur automatically when the program counter exceeds 7FFFh
(32K). If the EA pin is tied low, all program memory fetches are from external memory.
After ISP
Application
Security
level
Program Lock Bits
1
2
3
U: unprogrammed or "one" level.
P: programmed or "zero" level.
X: don’t care
WARNING: Security level 2 and 3 should only be programmed after Flash and code
verification.
LB0
U
P
X
Dedicated
ISP
After ISP
Application
LB1
U
U
P
Virgin
or
Protection Description
No program lock features enabled.
ISP programming of the Flash is disabled.
Same as 2, also verify through ISP programming interface is disabled.
After Parallel
Programming
Application
After Parallel
Programming
Dedicated
ISP
Application
Virgin
or
AT89C51IC2
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