The register's bits control such functions as selecting the channel to be converted, putting the device in power-down mode, and starting a conversion.
#Parallel to serial converter with buffer serial#
In this example, the DSP's serial port is used to program an internal 5-bit register in the ADC. The DSP usually (but not always) supplies an additional framing pulse that is active either for one cycle at the beginning of the communication or, as shown (TFS/RFS), for the duration of the transmission. To distinguish the bits of the serial data stream from one another, a clock signal (SCLK) must be provided, usually by the DSP However, sometimes the ADC supplies this clock as an output. The data stream also includes three additional bits that identify the input channel that the AD7890's multiplexer is currently selecting. The 12 bits that constitute the conversion result are transmitted as a serial data stream over a single line. Also shown is the timing sequence that the DSP uses to communicate with the ADC. The figure shows an AD7890 8-Channel multiplexed 12-bit serial A/D converter (ADC) connected to the serial port of an ADSP-2105 digital signal processor (DSP). In doing this we will dispel some myths about serial data converters. Let's start by looking at how a serial interface works and then compare it to a parallel interface. What do I need to know to choose and use one?Ī. I need data converters to fit in a tight space, and I suspect that a serial interface will help. Ask The Applications Engineer-19: Interfacing To Serial Converters-I