Datasheet

MC9S12XDP512 Data Sheet, Rev. 2.21

Freescale Semiconductor 515

Chapter 12

Serial Peripheral Interface (S12SPIV4)

12.1 Introduction

The SPI module allows a duplex, synchronous, serial communication between the MCU and peripheral

devices. Software can poll the SPI status ﬂags or the SPI operation can be interrupt driven.

12.1.1 Glossary of Terms

12.1.2 Features

The SPI includes these distinctive features:

• Master mode and slave mode

• Bidirectional mode

• Slave select output

• Mode fault error ﬂag with CPU interrupt capability

• Double-buffered data register

• Serial clock with programmable polarity and phase

• Control of SPI operation during wait mode

12.1.3 Modes of Operation

The SPI functions in three modes: run, wait, and stop.

• Run mode

This is the basic mode of operation.

• Wait mode

SPI

Serial Peripheral Interface

Slave Select

SCK

Serial Clock

MOSI

Master Output, Slave Input

MISO

Master Input, Slave Output

MOMI

Master Output, Master Input

SISO

Slave Input, Slave Output