A.2 Internal Data Memory
The internal data memory space is a total of 256 bytes of RAM, which includes the 128 bytes of special function
registers (SFR) space. The internal data memory space is mapped in accordance with the industry standard 8052
MCU. The internal data memory space is mapped from 00h to FFh with the SFRs mapped from 80h to FFh. The lower
128 bytes are accessible with both direct and indirect addressing. However, the upper 128 bytes, which is the SFR
space, is only accessible with direct addressing. Note that the internal data memory space is separate and distinct
from the external data memory space, and although both spaces begin at address 0000h, there is no overlap.
Program Memory
FFFFh
FFFFh
External Data Memory
Memory Mapped Registers
(80 Bytes)
FFB0h
FFAFh
24K 鈥?Reserved
FA10h
FA0Fh
USB End-Point Configuration
Blocks and Buffer Space
(1440 Bytes)
A000h
9FFFh
Boot ROM (8K)
58,000 Bytes 鈥?Reserved
8000h
7FFFh
24K 鈥?Reserved
1780h
177Fh
2000h
1FFFh
Boot ROM (8K)
0000h
0000h
Code RAM
(6016 Bytes)
(Read/Write)
Figure A鈥?. Boot Loader Mode Memory Map
A鈥?