Many members of the MSP430 family have integrated A/D converters (ADCs), but in someapplications the required analog conversion function is remote, optional, or perhaps anafterthought. In these types of applications, using external ADCs such as the low-cost, easy touse TLC549 and TLV1549 are options. This report demonstrates how to interface anMSP430F1121 to a TLC549. The TLC549 interfaces serially with the MSP430F1121 using threeI/O pins with no external components. This application report shows how to interface anMSP430F1121 and TLC549 using bit-by-bit software.· Only 31 bytes of MSP430 code for the TLC549 driver· Simple serial interface· A/D conversion complete in less than 17μs