Epson S1C63558 - Manual (Page 23)

S1C63558 TECHNICAL MANUAL EPSON 13
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 bits
4-bit access area
(SP2 stack area)
4-bit access area
(Data area)
4/16-bit access area
(SP1 stack area)
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.