Datasheet

MC68HC908QB8 Data Sheet, Rev. 3
Freescale Semiconductor 155
Chapter 15
Serial Peripheral Interface (SPI) Module
15.1 Introduction
This section describes the serial peripheral interface (SPI) module, which allows full-duplex, synchronous,
serial communications with peripheral devices.
The SPI shares its pins with general-purpose input/output (I/O) port pins. See Figure 15-1 for port location
of these shared pins.
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:
– SPRF (SPI receiver full)
– SPTE (SPI transmitter empty)
• Mode fault error flag with interrupt capability
• Overflow error flag with interrupt capability
• Programmable wired-OR mode