NES Controller Interface

About

• Written in Verilog-2005 using the lowRISC Verilog Coding Style
• Synthesizable with Yosys, Vivado, and more
• Number of controllers is parameterizable
• Used by UCSB IEEE Mapache 64 ( a custom 6502 video game console)

Module	Icestorm
nes_controller_interface#1	35 SB_LUT4 / 24 SB_DFF
nes_controller_interface#4	38 SB_LUT4 / 69 SB_DFF
nes_controller	8 SB_LUT4 / 8 SB_DFF

#define CONTROLLER_A_MASK       ((uint8_t)0x80)
#define CONTROLLER_B_MASK       ((uint8_t)0x40)
#define CONTROLLER_SELECT_MASK  ((uint8_t)0x20)
#define CONTROLLER_START_MASK   ((uint8_t)0x10)
#define CONTROLLER_UP_MASK      ((uint8_t)0x08)
#define CONTROLLER_DOWN_MASK    ((uint8_t)0x04)
#define CONTROLLER_LEFT_MASK    ((uint8_t)0x02)
#define CONTROLLER_RIGHT_MASK   ((uint8_t)0x01)

Notes

• Look at "sim/controller_interface_tb.v" for a reference on how to instantiate the module(s)
• NES Controllers allow being read up to 500 kHz. Go faster at your own risk
• You may have to increase the LATCH_PULSE_WIDTH parameter for higher frequencies
• The nes_controller module can be used for simulation

Downloading

To download the RTL using curl:

( echo '/*';
  curl -sL https://raw.githubusercontent.com/sifferman/nes_controller_interface/main/LICENSE | sed 's/^/ * /';
  echo ' */';
  curl -sL https://raw.githubusercontent.com/sifferman/nes_controller_interface/main/rtl/nes_controller_interface.v;
) > nes_controller_interface.v

( echo '/*';
  curl -sL https://raw.githubusercontent.com/sifferman/nes_controller_interface/main/LICENSE | sed 's/^/ * /';
  echo ' */';
  curl -sL https://raw.githubusercontent.com/sifferman/nes_controller_interface/main/rtl/nes_controller.v;
) > nes_controller.v

To add this repo as a FuseSoC library:

fusesoc library add nes_controller_interface https://github.com/sifferman/nes_controller_interface --sync-type=git

filesets:
  {fileset_name}:
    depend:
      - sifferman::nes_controller_interface

To make repository into a Git submodule:

git submodule add https://github.com/sifferman/nes_controller_interface <path/to/destination>

Run In This Repository

# Init FuseSoC
fusesoc library add sifferman__nes_controller_interface . --sync-type=local
# Lint with Verilator
fusesoc run --target lint sifferman::nes_controller_interface
# Simulate with Icarus
fusesoc run --target sim --tool icarus sifferman::nes_controller_interface
# Simulate with Verilator
fusesoc run --target sim --tool verilator sifferman::nes_controller_interface
# Synthesize Controller Interface with Icestorm for the iCE40HX-8K CT256
fusesoc run --target synth_interface sifferman::nes_controller_interface
# Synthesize Controller with Icestorm for the iCE40HX-8K CT256
fusesoc run --target synth_controller sifferman::nes_controller_interface