;Scrolling software idea for a 8 x 80bit LED matrix. Through this LED ;matrix a much bigger pixel matrix is scrolled. ;The pixel matrix contains 8 rows, each 48 bytes wide. The first 10 bytes ;represent the blank information, the remaining 38 bytes represent the ;text to be scrolled. ;From the pixel matrix, stored at address 7168, an 11 byte wide block is ;selected. The first 10 bytes of this block are fully shifted into the ;4096. From the 11th byte only a certain number (represented by "SHIFT" ;(=0..7)) is shifted into the 4094. ;The start address of this block depends on STRT_BYTE (=0..47),ROW_OFS_L, ;ROW_OFS_H (=0,48,96,144...336, by other words =ROW * 48) and the start ;address of pixel matrix (MATRX_STRT_L, MATRX_STRT_H). ;ROW (=0..7) defines the row to be shifted and displayed. ;The actual scroll position is represented by INDEX_L,INDEX_H (=0..383). ;This INDEX is "0", when the blank block is fully shifted into the 4094 ;and the text is just not yet visible. ;REFRESH is incremented when a full set of 8 rows has been displayed. ;When REFRESH equals SCRL-RATE, then the display is scrolled by one ;pixel column. This is every 16 * 8 * 950µsec = 0.12sec here, assuming ;11.0592MHz clock speed. Adjust SCRL_RATE to change the scroll speed. $NOMOD51 $INCLUDE (89s52.mcu) DATA_OUT BIT P1.0 CLOCK BIT P1.1 STROBE BIT P1.2 ANODE_DRIV DATA 30H INDEX_L DATA 31H INDEX_H DATA 32H REFRESH DATA 33H ROW DATA 34H ROW_OFS_L DATA 35H ROW_OFS_H DATA 36H SHIFT DATA 37H STRT_BYTE DATA 38H SCRL_RATE EQU 16 MATRX_STRT_L EQU 00H MATRX_STRT_H EQU 1CH ORG 0 SJMP Start ORG 002BH Start: MOV AUXR,#00011001B ;AT89S52 specific status byte MOV TMOD,#00000001B ;Configure Timer 0 (Mode 1) MOV TH0,#252 ;Set 950µsec MOV TL0,#148 SETB TR0 ;Start Timer 0 CLR CLOCK ;Prepare the first shifting Initialize: CLR A ;Set registers to "0" MOV STRT_BYTE,A MOV ROW,A MOV ROW_OFS_L,A MOV ROW_OFS_H,A MOV INDEX_L,A MOV INDEX_H,A MOV REFRESH,A MOV SHIFT,A MOV ANODE_DRIV,#11111110B ;Prepare ANODE_DRIV for first ;row. Main_loop: MOV WDTRST,#01EH ;Feed the watchdog MOV WDTRST,#0E1H MOV R6,#10 ;10 pixel bytes to be selected and ;shifted. MOV R7,STRT_BYTE ;Copy STRT_BYTE into R7 MOV A,MATRX_STRT_L ;Fabricate the start address of 11 ADD A,ROW_OFS_L ;bytes wide block. MOV DP0L,A ;Feed the DPTR with the base address MOV A,MATRX_STRT_H ;and use R7 as a "looping" address ADDC A,ROW_OFS_H ;offset. MOV DP0H,A Get_bytes: MOV A,R7 ;R7 contains the address offset MOV AUXR1,#0 ;89S52 needs DPTR to be defined MOVC A,@A+DPTR ;Fetch the pixel byte MOV R5,#8 ;All 8 bits of pixel byte Shift_loop1: RLC A ;Shift the pixel byte fully into MOV DATA_OUT,C ;the 4094. SETB CLOCK CLR CLOCK DJNZ R5,Shift_loop1 ;All 8 bits shifted? INC R7 ;Address the next pixel byte CJNE R7,#48,Repeat ;If end of pixel matrix is reached, MOV R7,#0 ;fetch it from the begin again. Repeat: DJNZ R6,Get_bytes ;First 10 pixel bytes shifted? MOV R5,SHIFT ;Copy SHIFT into R5 CJNE R5,#0,Last_byte ;11th pixel byte to be shifted? SJMP Wait ;11th pixel byte need not to be ;shifted into the 4094. Last_byte: MOV A,R7 ;R7 addresses the 11th pixel byte MOV AUXR1,#0 ;89S52 needs DPTR to be defined MOVC A,@A+DPTR ;Fetch the 11th pixel byte Shift_loop2: RLC A ;11.pixel byte is partially shifted MOV DATA_OUT,C ;into the 4094. SHIFT represents SETB CLOCK ;the number of bits to be shifted. CLR CLOCK DJNZ R5,Shift_loop2 Wait: JNB TF0,Wait ;Timer 0 overrun? MOV P0,#255 ;Turn-off the anode drivers CLR TR0 ;Stop Timer 0 CLR TF0 ;Reset timer flag bit (TF0) MOV TMOD,#00000001B ;Configure Timer 0 (Mode 1) MOV TH0,#252 ;Set 950µsec MOV TL0,#148 SETB TR0 ;Start Timer 0 SETB STROBE ;Latch the new column data in CLR STROBE ;the 4094s. MOV A,ANODE_DRIV ;Copy ANODE_DRIV into A MOV P0,A ;Turn-on selected anode driver RL A ;Prepare ANODE_DRIV for next row MOV ANODE_DRIV,A INC ROW ;Prepare next row MOV A,ROW_OFS_L ;Fabricate next ROW_OFS_L/H address ADD A,#48 MOV ROW_OFS_L,A MOV A,ROW_OFS_H ADDC A,#0 MOV ROW_OFS_H,A MOV A,ROW CJNE A,#8,Go_back ;All 8 rows shifted? CLR A ;8 rows shifted, so reset ROW MOV ROW,A ;and ROW_OFS_L/H MOV ROW_OFS_L,A MOV ROW_OFS_H,A INC REFRESH ;and increment REFRESH. MOV A,REFRESH CJNE A,SCRL_RATE,Go_back ;Time to scroll? SJMP Prepare_scroll Go_back: LJMP Main_loop ;Jump back and shift the next row Prepare_scroll: MOV REFRESH,#0 ;Reset REFRESH MOV A,INDEX_L ;Increment INDEX_L/H ADD A,#1 MOV INDEX_L,A MOV A,INDEX_H ADDC A,#0 MOV INDEX_H,A INC SHIFT ;Increment SHIFT MOV A,SHIFT CJNE A,#8,Go_back ;SHIFT to be reseted? MOV SHIFT,#0 ;Reset SHIFT and INC STRT_BYTE ;increment STRT_BYTE. MOV A,INDEX_L ;INDEX_L/H = 384? CJNE A,#128,Go_back ;No,so go back and shift next row MOV A,INDEX_H CJNE A,#1,Go_back LJMP Initialize ;INDEX_L/H = 384,so initialize and ;start all over again. org 7168 DB 0,0,0,0,0,0,0,0,0,0 ;Uppermost row of pixel matrix DB 255,255,255,255,255 ;"0" represents the blank pixels, DB 255,255,255,255,255 ;"255" the character pixels. DB 255,255,255,255,255 DB 255,255,255,255,255 ;Each row contains 48 bytes DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255 DB 0,0,0,0,0,0,0,0,0,0 ;2.row of pixel matrix DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255 DB 0,0,0,0,0,0,0,0,0,0 ;3.row of pixel matrix DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255 DB 0,0,0,0,0,0,0,0,0,0 ;4.row of pixel matrix DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255 DB 0,0,0,0,0,0,0,0,0,0 ;5.row of pixel matrix DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255 DB 0,0,0,0,0,0,0,0,0,0 ;6.row of pixel matrix DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255 DB 0,0,0,0,0,0,0,0,0,0 ;7.row of pixel matrix DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255 DB 0,0,0,0,0,0,0,0,0,0 ;8.row of pixel matrix DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255,255,255 DB 255,255,255 end