October 9, 2006 SPI 4

### NAME

spi - introduction to machine-independent SPI bus support and drivers

### SYNOPSIS

spi* at mainbus?

Other attachments are machine-dependent and will depend on the bus topology of your system. See intro(4) for your system for more information.

### DESCRIPTION

NetBSD includes a machine dependent SPI (Serial Peripherial Interface) bus subsystem, and several different machine-independent SPI device drivers.

Your system may support additional machine-dependent SPI devices. Consult your system's intro(4) for additional information.

SPI is a 4-wire synchronous full-duplex serial bus. Some systems provide support for Microwire, which is Philips' name for a strict subset of SPI, with more rigidly defined signaling. Therefore, Microwire devices are also supported by the SPI framework.

Note that when referencing SPI devices in a config(1) file, the `slave' must be provided, as SPI lacks any way to automatically probe devices.

### HARDWARE

NetBSD includes the following machine-independent SPI drivers

m25p
  STMicroelectronics M25P family of NOR flash devices.

tm121temp
  Texas Instruments TMP121 temperature sensor.

### SEE ALSO

m25p(4), tm121temp(4)

### HISTORY

The machine-independent SPI framework was written by Garrett D'Amore
for the Champaign-Urbana Community Wireless Network Project (CUWiN), and appeared in NetBSD4.0.