LED PWM IP Demo

LED PWM IP Demo for iCESugar (using iCE40UP5K)

Introduction

This demo use iCELink (embedded in iCESugar) to send commands, then to control RGB PWM IP. RGB PWM hard IP is embedded in iCE40 UltraPlus. You can refer to iCE40 LED Driver Usage Guide for more information.

Every command contains two bytes, the first one is address, and the second one is data. The baudrate is 115200.

When address is in a range of 0x00 - 0x0F, this command will be sent directly to LED PWM IP via LEDDADDR/LEDDDAT interface. When command received, LEDDCS and LEDDDEN will shortly set in one cycle and write to IP.

When address is in a range of 0x10 - 0xFF, this command will be used to modify LEDDEXE. When data is 0, LEDDEXE will be cleared, otherwise LEDDEXE will be set.

For this demo, signal list is below.

Signal	Direction	Pin Number	Description
clk_12m	input	35	clock derived from iCELink (MCO)
rxd	input	4	received data from iCELink
pwm[0:2]	output	[18:21]	PWM signals, could be used to analysis
rgb[0:2]	output	[39:41]	RGB LED (dedicated pins)

Generate synthesizable code

Use SpinalHDL to generate Verilog file. Make sure sbt is installed.

sbt run

After synthesis, LedPwmDemo.v is generated.

You can modify LedPwmDemo.scala to adjust current sinks for LED.

Synthesis, P&R, and generate bitstream

Use LedPwmDemo.v, top.v and top.pcf to generate bitstream.

LED_PWM_IP_Demo.bin is generated by iCEcube2. icestorm could be used to generate bitstream, I suppose.

For iCESugar, the generated bitstream can be copied to iCELink. Make sure J3 is in 'Prog Flash' state.

Demo Application

led_test.py can be used to test LED PWM IP. Following is required:

Python 3
PySerial
Tkinter

To run this demo, enter device path to device (COMx for Windows, or /dev/ttyX for *nix), connect to iCELink, and click LED ON.

To adjust parameters, please refer to iCE40 LED Driver Usage Guide for more information.