T89C51CC01 Atmel, T89C51CC01 Datasheet - Page 26

• Manufacturer Part Number: T89C51CC01
• Description: Enhanced 8-Bit Microcontroller
• Manufacturer: Atmel

Data Memory
26
T89C51CC01
The T89C51CC01 provides data memory access in two different spaces:
1. The internal space mapped in three separate segments:
•
•
•
2. The external space.
A fourth internal segment is available but dedicated to Special Function Registers,
SFRs, (addresses 80h to FFh) accessible by direct addressing mode.
Figure 11 shows the internal and external data memory spaces organization.
Figure 10. Internal Memory - RAM
Figure 11. Internal and External Data Memory Organization XRAM-XRAM
the lower 128 Bytes RAM segment.
the upper 128 Bytes RAM segment.
the expanded 1024 Bytes RAM segment (XRAM).
00h
256 up to 1024 Bytes
Internal XRAM
Internal
EXTRAM = 0
FFh
7Fh
80h
00h
indirect addressing
direct or indirect
Internal RAM
Internal RAM
addressing
128 Bytes
128 Bytes
Upper
Lower
FFh or 3FFh
FFh
80h
direct addressing
FFFFh
0000h
Registers
Function
Special
External XRAM
External
EXTRAM = 1
64K Bytes
4129K–CAN–01/05