CHAPTER 3: CPU, ROM, RAM

(3)Subroutine calls use 4 words (for PC evacuation) in the stack area for 16-bit data (SP1). Interrupts use 4 words (for PC evacuation) in the stack area for 16-bit data (SP1) and 1 word (for F register evacua- tion) in the stack area for 4-bit data.

0000H

00FFH

0100H

01FFH

0200H

13FFH

4-bit access area (SP2 stack area)

4/16-bit access area (SP1 stack area)

4-bit access area (Data area)

4 bits

Fig. 3.3.1 Configuration of data RAM

3.4 Data ROM

The data ROM is a mask ROM for loading various static data such as a character generator, and has a capacity of 2,048 words ⋅ 4 bits. The data ROM is assigned to addresses 8000H to 87FFH on the data memory map, and the data can be read using the same data memory access instructions as the RAM.

S1C63558 TECHNICAL MANUAL

EPSON

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