microprocessor aid

76 microprocessor aid Faultfinding in microprocessor sys- tems is an arduous and time- consuming task. It would be a great help if it were possible to display the information on the data and address bus of the processor. And that is exactly what the circuit described here does: the conversion of data and address into hexadecimal code onto six displays. The displays are controlled by an IC which combines all the necessary functions: the 9368. This IC accepts a four-bit binary code, converts it into the corresponding hexadecimal number and makes it visible on a seven-segment LED display. A latch "memory" is also provided and the LED display is controlled directly by the IC. From figure 1 it will be seen that, apart from the six ICs and six displays, nothing further is required. The power requirement is 5 V at 750 mA. The printed circuit board for the aid is shown in figure 2. After all components have been mounted, the circuit is connected to the microprocessor. This is made easier ...