Chapter 15

Serial Peripheral Interface Module (SPI)

15.1 Introduction

The serial peripheral interface (SPI) module allows full-duplex, synchronous, serial communications with peripheral devices.

15.2 Features

Features of the SPI module include:

•Full-duplex operation

•Master and slave modes

•Double-buffered operation with separate transmit and receive registers

•Four master mode frequencies (maximum = bus frequency ⎟ 2)

•Maximum slave mode frequency = bus frequency

•Serial clock with programmable polarity and phase

•Two separately enabled interrupts with central processor unit (CPU) service:

–SPRF (SPI receiver full)

–SPTE (SPI transmitter empty)

•Mode fault error flag with CPU interrupt capability

•Overflow error flag with CPU interrupt capability

•Programmable wired-OR mode

•I2C (inter-integrated circuit) compatibility

15.3 Pin Name Conventions

The generic names of the SPI input/output (I/O) pins are:

•SS, slave select

•SPSCK, SPI serial clock

•MOSI, master out/slave in

•MISO, master in/slave out

SPI pins are shared by parallel I/O ports or have alternate functions. The full name of an SPI pin reflects the name of the shared port pin or the name of an alternate pin function. The generic pin names appear in the text that follows. Table 15-1shows the full names of the SPI I/O pins.

Table 15-1. Pin Name Conventions

 

 

 

 

 

 

 

 

 

 

Generic Pin Names:

MISO

MOSI

SPSCK

 

 

SS

 

Full Pin Names:

 

 

 

 

 

 

 

 

 

PTF3/MISO

PTF2/MOSI

PTF0/SPSCK

 

 

 

 

 

 

PTF1/SS

 

 

 

 

 

 

 

 

 

 

 

 

MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Freescale Semiconductor

 

 

 

 

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Freescale Semiconductor MC68HC908MR16, MC68HC908MR32 Chapter Serial Peripheral Interface Module SPI, Pin Name Conventions
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MC68HC908MR16, MC68HC908MR32 specifications

Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are part of the popular HC08 family, designed primarily for embedded applications. These microcontrollers are particularly favored in automotive, industrial, and consumer product sectors due to their reliability and versatility.

One of the standout features of the MC68HC908MR series is its CMOS technology, which enhances performance while minimizing power consumption. This makes these microcontrollers suitable for battery-operated devices. They operate at a maximum clock frequency of 2 MHz and offer a 16-bit architecture, providing a solid balance between processing power and efficiency.

The MC68HC908MR32 variant is equipped with 32KB of flash memory, which allows for the storage of complex programs and extensive data handling. In contrast, the MC68HC908MR16 features 16KB of flash memory, making it ideal for simpler applications. Both microcontrollers also come with 1KB of RAM, enabling efficient data processing and real-time operations.

Another significant characteristic of these microcontrollers is their integrated peripherals. They come with multiple input/output (I/O) pins, which allow for connectivity with various sensors and actuators. The built-in timer systems offer precise timing control for automotive and industrial applications, while the Analog-to-Digital Converter (ADC) provides essential conversion capabilities for various analog signals.

For communication purposes, the MC68HC908MR series includes a serial communication interface, enabling easy integration with other devices and systems. This versatility facilitates the development of complex systems that require interaction with external components.

Security is another crucial aspect of these microcontrollers. They have built-in fail-safe mechanisms to ensure reliable operation under various conditions, making them suitable for critical systems. Additionally, their robust architecture helps to safeguard against potential disruptions or attacks.

In summary, Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are key players in the embedded systems landscape. Their blend of power efficiency, integrated features, and scalability ensures they remain relevant for a wide array of applications, making them a favored choice among engineers and developers looking for dependable solutions in a competitive market.
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