Instruction Manual

Preliminary W79E8213/W79E8213R Data Sheet
Publication Release Date: July 11, 2008
- 11 - Revision A2
7.3 Data Memory (accessed by MOVX)
Not available in this product series.
7.4 Scratch-pad RAM and Register Map
As mentioned before the W79E8213 series have separate Program and Data Memory areas. The on-
chip 128 bytes scratch pad RAM is in addition to the external memory. There are also several Special
Function Registers (SFRs) which can be accessed by software. The SFRs can be accessed only by
direct addressing, while the on-chip RAM can be accessed by either direct or indirect addressing.
Figure 7-2: W79E8213 RAM and SFR memory map
Since the scratch-pad RAM is only 128 bytes it can be used only when data contents are small. There
are several other special purpose areas within the scratch-pad RAM. These are described as follows.