8051 Typical Interface Circuit - static display circuit diagram Parallel Extensions

 The following figure shows the parallel expansion static display circuit diagram (3 LED static display circuit), the figure compiled display routines, displays the number (≤255) in the presence of the RAM 30H.

 

    Appropriate procedures for:
　　DIR1: MOV A, 30H; reading shows the number of

　　MOV B, # 100; set divisor

　　DIV AB; produce one hundred display numbers

　　MOVC A, @ A + DPTR; display character read one hundred

　　MOV DPTR, # 0DFFFH; set 74 377 (one hundred) address

　　MOVX @ DPTR, A; output one hundred display character

　　MOV A, B; reading remainder

　　MOV B, # 10; divisor set

　　DIV AB; produce ten display numbers

　　MOV DPTR, # TAB; set common anode field code table first site

　　MOVC A, @ A + DPTR; reading ten character display

　　MOV DPTR, # 0BFFFH; set 74377 (ten) address

　　MOVX @ DPTR, A; output ten character display

　　MOV A, B; reading bits display digital

　　MOV DPTR, # TAB; set common anode field code table first site

　　MOVC A, @ A + DPTR; reading a bit display characters

　　MOV DPTR, # 7FFFH; set 74377 (a bit) address

　　MOVX @ DPTR, A; output bit display characters

　　RET;

　　TAB: DB 0C0H, 0F9H, 0A4H, 0B0H, 99H; common anode field code table

　　DB 92H, 82H, 0F8H, 80H, 90H;