The MSP430 is a famous series of 16-bit controllers from Texas Instruments. They are mainly used for battery-powered and low-cost based projects. The article aims at interfacing a popular series for DAC named as DAC7564, which is also manufactured by Texas Instruments as well as other semiconductor corporations. The DAC7564 is a low-power, voltage-output, and four-channel, 12-bit digital-to-analog converter (DAC). The device includes a 2.5V, 2ppm/°C internal reference. The device is monotonic, provides very good linearity, and minimizes undesired code-to-code transient voltages (glitch).
An N-bit string DAC simply consists of 2N equal resistors in series and 2N switches (usually CMOS), one between each node of the chain and the output. The output is taken from the appropriate tap by closing just one of the switches. An MSP430 is used to send the data and the SPI communication is done by bit-banging. A library provides functions to send, receive and transfer data using SPI protocol. Being a bit-bang communication there is no particular hardware module necessary and any MSP430 would work, in this particular case a MSP430F2274 is used.