Datasheet

38
AT89C51AC3
4383D–8051–02/08
Program/Code
Memory
The AT89C51AC3 implement 64K Bytes of on-chip program/code memory. Figure 20
shows the partitioning of internal and external program/code memory spaces depending
on the product.
The Flash memory increases EPROM and ROM functionality by in-circuit electrical era-
sure and programming. Thanks to the internal charge pump, the high voltage needed for
programming or erasing Flash cells is generated on-chip using the standard VDD volt-
age. Thus, the Flash Memory can be programmed using only one voltage and allows In-
System Programming commonly known as ISP. Hardware programming mode is also
available using specific programming tool.
Figure 20. Program/Code Memory Organization
0000h
64K Bytes
FFFFh
internal
0000h
FFFFh
Flash
64K Bytes
external
memory
EA = 0
EA = 1