Using serial peripherals
In Part E we consider how two powerful and influential serial communication protocols (‘I2C’ and ‘SPI’) may be utilized in applications with a time-triggered architecture.
Use of these protocols has two main advantages:
● They are designed to allow microcontrollers to be linked to a wide range of different peripherals – memory, displays, ADCs and similar devices – without requiring the use of large numbers of port pins.
● A common set of software code may be used with all SPI peripherals (for example), reducing the development effort required.
In Chapter 23, we consider the I2C bus, developed by Philips. I2C is a simple protocol, and may be easily generated in software. This allows the full range of 8051 devices (including Small 8051s, with very few spare port pins) to communicate with a wide range of peripheral devices.
In Chapter 24, we consider the SPI bus, developed by Motorola. Increasing numbers of ‘Standard’ and ‘Extended’ 8051 devices have hardware support for SPI and we will make use of these facilities in Chapter 24.