3.7. Test Chip IP

Chipyard includes a Test Chip IP library which provides various hardware widgets that may be useful when designing SoCs. This includes a Serial Adapter, Block Device Controller, TileLink SERDES, TileLink Switcher, and UART Adapter.

3.7.1. Serial Adapter

The serial adapter is used by tethered test chips to communicate with the host processor. An instance of RISC-V frontend server running on the host CPU can send commands to the serial adapter to read and write data from the memory system. The frontend server uses this functionality to load the test program into memory and to poll for completion of the program. More information on this can be found in Chipyard Boot Process.

3.7.2. Block Device Controller

The block device controller provides a generic interface for secondary storage. This device is primarily used in FireSim to interface with a block device software simulation model. The default Linux configuration in firesim-software

To add a block device to your design, add HasPeripheryBlockDevice to your lazy module and HasPeripheryBlockDeviceModuleImp to the implementation. Then add the WithBlockDevice config mixin to your configuration.

3.7.5. UART Adapter

The UART Adapter is a device that lives in the TestHarness and connects to the UART port of the DUT to simulate communication over UART (ex. printing out to UART during Linux boot). In addition to working with stdin/stdout of the host, it is able to output a UART log to a particular file using +uartlog=<NAME_OF_FILE> during simulation.

By default, this UART Adapter is added to all systems within Chipyard by adding the CanHavePeripheryUARTWithAdapter and CanHavePeripheryUARTWithAdapterImp traits to the Top system. These traits add a SiFive UART to the system as well as add the UART Adapter to the TestHarness.