Thomas' Labs

SPI for microprocessors

Bremen, Germany,

SPI is a useful serial communications interface. It is used in hobbyist projects to control from memory ICs to LCD screens and it's even possible to read SD cards through it.

Most modern microcontrollers are equiped with built-in SPI support, which can be easily used from code without much hardware required. But what happends when one wants to interface SPI peripherals with old microprocessors? These usually don't have any built-in peripherals and , as far as I am aware, there are no enternal peripherals one can buy.

This article aims to provide an overview of how SPI works, the instructions on how to build a SPI module for old microprocessors like the Z80 and the explanation of how such a module operates.

This is also a part of my ongoing series on the progress of my Z80 based project.

Table of Contents

1. How does SPI work