SEGA SATURN DEVELOPER'S MANUAL

3.2 SCU: SCU smoothly executes the interface of multiple processors connected to CPU-bus, A-bus, and B-bus. Furthermore, a DMA controller, interrupt controller, and DSP are installed inside.
System configuration: The CPU-bus is connected to the SMPC and controls the system reset signal and control pad.
∙ A-bus is connected to devices that supply programs such as cartridges and CDs.
∙ The SCU interrupt controller controls interrupts from A-bus, B-bus, and SMPC. Timer interrupts are supported, and interrupts (INT signals) can be generated in synchronization with the screen display (Figure 3.1).
Figure 3.1 SCU system configuration

3.2 SCU