TT06: FazyRV-ExoTiny

This TinyTapeout implements a System-on-Chip (SoC) design based on the FazyRV RISC-V core. Within this repository, all workflows and port bindings for TT06 are located. Documentation on the SoC can be found in meiniKi/FazyRV-ExoTiny. For details on the FazyRV core, please refer to meiniKi/FazyRV.

• Instantiates FazyRV with a chunk size of 2 bits.
• Uses external instruction memory (QSPI ROM) and external data memory (QSPI RAM).
• Provides 6 memory-mapped general-purpose outputs and 7 inputs.
• Provides an SPI peripheral with programmable CPOL and a buffer of up to 4 bytes.

Pin	Description	Note
clk	Clock	up to 50MHz
rst_n	Reset	low active

Important

rst_n is not synchronized. Make sure it is released sufficient hold time after the rising clock edge and sufficient setup time before the falling edge. Do not release reset while clk is low. The design appears to be on the edge of implementability. An additional dff breaks convergence.

Pin Description

Pin	Description	Reset State
in6 ... in0	General purpose inputs	high-z
in7	(User) SPI SDI	high-z
bi0	CS ROM (low active)	high-z
bi1	(Memory) QSPI SDIO0	high-z
bi2	(Memory) QSPI SDIO1	high-z
bi3	(Memory) QSPI SCK	high-z
bi4	(Memory) QSPI SDIO2	high-z
bi5	(Memory) QSPI SDIO3	high-z
bi6	CS RAM (low active)	high-z
bi7	NC	high-z
ot5 ... ot0	General purpose outputs	0 (low)
ot6	(User) SPI SCK	0/1 depending on CPOL
ot7	(User) SPI SCK	0 (low)

Memory Map and SoC Description

Further documentation can be found at meiniKi/FazyRV-ExoTiny.

Quick Start

Init the Repo

git submodule update --init --recursive

Run Preprocessing

make preproc

Run Simulation

make sim

The sim target builds the risc-v tests in FazyRV-ExoTiny/sim/firmware and executes them on the pre-processed SoC design and the testbench in tb.

Run Cocotb Simulation

make sim.cocotb.default
# or
make sim.cocotb.gl
# to run gate level simulation. Needs gate_level_netlist.v to be copied to `test` 

The cocotb simulation is designed to also work with the post-synthesized design. Thus, it provides less debugging information and is only recommended to be used after make sim passes.