There is an 8031 chip, which is expanded by an 8255A. If port B of 8255A is used as input, each bit of port B is connected to a switch, and port A is used as output, each bit is connected to a light-emitting diode, please draw the circuit schematic diagram, and write a program so that when a switch of port B is connected to a high level, the corresponding light-emitting diode of port A will be lit.
A: 7ffch
B: 7ffdh
C:7ffeh
Control port: 7fffh
MOV DPTR,#7FFFH
MOV A,#10000010B
MOV @DPTR,A
MOV DPTR,#7FFDH
MOVX A,@DPTR
MOV DPTR,#7FFCH
MOVX @DPTR,A
Picture 1
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