The Digilent Pmod is used to connect low frequency, low I/O pin count peripheral modules to host controller boards. There are 6-pin and 12-pin versions of the interface defined. The 6-pin version provides four digital I/O signal pins, one power pin and one ground pin. The 12-pin version provides eight I/O signal pins, two power pins and two ground pins. The signals of the 12-pin version are arranged so that it provides two of the six-pin interfaces stacked.
In general, Pmod peripheral modules can plug directly into connectors on the host controller board, or be connected to the controller board via 6-pin or 12-pin cables. Two 6-pin peripheral modules can be connected to a single 12-pin host connector via a 12-pin to dual 6-pin splitter cable.
Similarly, a single 12-pin peripheral module can be connected to two 6-pin host connectors via the same 12-pin to dual 6-pin splitter cable.
Pmod peripheral modules are powered by the host via the interface’s power and ground pins. The Pmod is not intended for high frequency operation. In addition to the 6 and 12 pin interfaces, the Pmod peripheral module interface also encompasses a variant using the I2C interface, and two or four wire MTE cables. In some cases, an I2C connected module can be connected directly to a Pmod connector on a system board, but generally the connection will be via MTE cables. The Pmod I2C interface provides the two I2C signals, SDA and SCL, plus power and ground.