Chapter 3 Functions

■ 3.1 CPU

A 32-bit RISC chip with a built-in DSP function is mounted on the main CPU, and a 16-bit CPU MC68EC000 is mounted on the sound block section. Moreover, SH-1 is carried in the subsystem side.

Table 3.1 CPU specifications

SH-2	・ RISC type instruction set ・ Internal and external 32-bit bus cache 4K bytes ・ Clock 28.6MHz Note 1 ・ Built-in multiplier / divider
SH-1	・ RISC type instruction set ・ Built-in A / D converter ・ Internal 32-bit bus, external 16-bit bus ・ Clock 20MHz ・ Cache 4K bytes ・ Built-in multiplier
MC68EC000	・ Internal 16-bit bus, external 16-bit bus ・ CISC type instruction set ・ Clock 11.3MHz

note

Table 3.1.1 SH-2 clock details

Screen display mode	Operating clock
320 dot mode (NTSC method)	26.8741 MHz
352 In dot mode (NTSC method)	28.6364 MHz
320 dot mode (PAL method)	26.6877 MHz
352 In dot mode (PAL method)	28.4377 MHz