U1
5A22-02
CPU
QFP-100 (0.65 mm pitch)
Main CPU
About this component
The 5A22 (marked S-CPU) runs game code and handles the controller ports, DMA, HDMA, timers and hardware multiply/divide. It speeds up or slows down depending on the memory region accessed, from 1.79 MHz to 3.58 MHz. Consolemods notes that early SHVC-CPU-01 boards are prone to CPU/PPU faults. On 1CHIP boards this chip does not exist as a separate part because it is merged into the S-CPUN. Part variants: Early SHVC-CPU-01 boards use S-CPU 5A22-01 (has a DMA/HDMA crash bug); later 3-chip boards use 5A22-02 (S-CPU A/B). 1CHIP boards replace the CPU and both PPUs with S-CPUN (RF5A122).
What it does on this board
65C816-based 16-bit CPU running up to 3.58MHz.
Pinout & readings
No pinout or reference readings yet — these show what each pin does and what a healthy part should measure.