Tools

A general device interface, such as A/D, D/A, I/O, and so on, is required for the interaction between the embedded system and the outside world. The peripherals connect to various devices or sensors outside the chip to implement the microprocessor's input/output. Typically, each peripheral serves only one purpose. It might be external to the chip or internal to the chip. Peripherals come in a variety of shapes and sizes, ranging from simple serial communication devices to very complicated 802.11 wireless devices.

A/D (analog/digital conversion interface) and D/A (digital/analog conversion interface) are common device interfaces in embedded systems, while I/O interfaces include RS-232 (serial communication interface), Ethernet (Ethernet interface), USB (universal serial bus interface), audio interface, VGA video output interface, I2C (field bus), SPI (serial peripheral interface), and IrDA (infrared interface), etc.