In Chapter 5, we saw how a microprocessor (MPU), under software control, transfers data to an external register. The circuit diagram is repeated in Figure 8-69. Once the data are in the register, they are stored there and used for whatever purpose they are needed. Sometimes, each individual bit in the register has a unique function. For example, in automobile computers, each bit could represent the status of a different physical variable being monitored by the MPU. One bit might indicate when the engine temperature is too high. Another bit might signal when oil pressure is too low. In other applications, the bits in the register are used to produce an analog output that can be used to drive devices requiring analog inputs that have many different voltage levels. Sketch the waveform from the DAC. executing a program that is transferring a new set of data to the register every 10 μs according to Table 8-15. Sketch the resulting waveform at V_OUT.

Figure 8-69

Table 8-15

Do 2 D CLK D D CLK CLK CLK X X Xo