An award winning CPU design fit into the GF180 MPW0 Shuttle.
To keep the design simple this project places a Serv CPU with a scan-chain around it connecting it's wishbone bus which is a combination of data and instructions out via I/O pins.
Another I/O pin is responsible for handling clock and reset. Operation will run as follows:
- Using an external controller, load in default values for the wishbone bus, bring serv out of reset and clock it.
- Latch in and scan out the wishbone bus values. Handle any requests.
- Scan in data from the request and clock serv.
- Goto 2.
In this manner we should be able to implement external peripherals like UARTs, timers, and GPIOs. The external controller can be a microcontroller, FPGA, or the caravel harness SoC.