Page 124 - DCAP210_INTRODUCTION__TO_MICROPROCESSORS

Introduction to Microprocessors

Notes
Figure 8.1: Control Circuit

8.3.9 Interfacing the LEDs (Latch & LEDs)

Figure 8.2: Latch & LEDs

8.3.10 Interfacing the LEDs (The Program)

• When a bit on the AD bus is 1, the corresponding Q’ will be zero and the LED will have 5
volts on the anode and 0 on the cathode. Therefore, it will be on.

• Finally, to write the program:
MVI A, Data ;load the data to be displayed
OUT FF ;send the data to output port FF
HLT ;End

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