Table of Contents
Project to replace CTC
CTC (U4) is typically not populated in Z80retro, so this is a project to replace CTC with basic baud rate generation for 57600 and 2400 baud clocks and reuse CTC space for expanded I/O functions. The expanded functions are I2C, SPI/SD, WS2812B driver, and DS1302 RTC.
Prototype schematic
CPLD design files
CPLD design file in PDF schematic
Memory map: $40 is I2C, $41 is SPI, $42 is WS2812, $43 is RTC
Software
I2C
Display ASCII table, scrolling
Game of Life
SPI
WS2812B
DS1302 RTC
Analog clock