I am not understanding the program below ,can anyone help
Unipolar full step Stepper motor: _ _
INPUT SEQUENCE: X Y X Y
1 1 0 0
0 1 1 0
0 0 1 1
1 0 0 1
8255 CONTROL WORD: 1 0 0 0 0 0 0 0 =80H [COLOR=Blue]this instructs the 8255A to set all its PORT pins to outputs...[/COLOR]
PROGRAM:
MVI A, 80; 10000000
OUT port B
START MVI A, FC; 11111100
OUT port A; place 11111100 on PORTA pins
CALL DELAY
MVI A, F6; 11110110 on PORTA pins
OUT port A
CALL DELAY
MVI A, F3; 11110011 on PORTA pins
OUT port A
CALL DELAY
MVI A, F9; 11111001 on PORTA pins
OUT port A
JMP START
DELAY LXI D, 0003
CALL DELAY
RET