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https://opencores.org/ocsvn/eco32/eco32/trunk
Subversion Repositories eco32
[/] [eco32/] [tags/] [eco32-0.22/] [monitor/] [monitor-digilent/] [display.s] - Rev 143
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; ; display.s -- a memory-mapped alphanumerical display ; ;*************************************************************** .set dspbase,0xF0100000 ; display base address .export dspinit ; initialize display .export dspoutchk ; check for output possible .export dspout ; do display output ;*************************************************************** .code .align 4 ; initialize display dspinit: sub $29,$29,4 stw $31,$29,0 jal clrscr add $8,$0,scrrow stw $0,$8,0 add $8,$0,scrcol stw $0,$8,0 jal calcp jal stcrs ldw $31,$29,0 add $29,$29,4 jr $31 ; check if a character can be written dspoutchk: add $2,$0,1 jr $31 ; output a character on the display dspout: sub $29,$29,8 stw $31,$29,4 stw $16,$29,0 and $16,$4,0xFF jal rmcrs add $8,$0,' ' bltu $16,$8,dspout2 add $8,$0,scrptr ldw $9,$8,0 or $16,$16,0x07 << 8 stw $16,$9,0 add $9,$9,4 stw $9,$8,0 add $8,$0,scrcol ldw $9,$8,0 add $9,$9,1 stw $9,$8,0 add $10,$0,80 bne $9,$10,dspout1 jal docr jal dolf dspout1: jal stcrs ldw $16,$29,0 ldw $31,$29,4 add $29,$29,8 jr $31 dspout2: add $8,$0,0x0D bne $16,$8,dspout3 jal docr j dspout1 dspout3: add $8,$0,0x0A bne $16,$8,dspout4 jal dolf j dspout1 dspout4: add $8,$0,0x08 bne $16,$8,dspout5 jal dobs j dspout1 dspout5: j dspout1 ; do carriage return docr: sub $29,$29,4 stw $31,$29,0 add $8,$0,scrcol stw $0,$8,0 jal calcp ldw $31,$29,0 add $29,$29,4 jr $31 ; do linefeed dolf: sub $29,$29,4 stw $31,$29,0 add $8,$0,scrrow ldw $9,$8,0 add $10,$0,29 beq $9,$10,dolf1 add $9,$9,1 stw $9,$8,0 jal calcp j dolf2 dolf1: jal scrscr dolf2: ldw $31,$29,0 add $29,$29,4 jr $31 ; do backspace dobs: sub $29,$29,4 stw $31,$29,0 add $8,$0,scrcol ldw $9,$8,0 beq $9,$0,dobs1 sub $9,$9,1 stw $9,$8,0 jal calcp dobs1: ldw $31,$29,0 add $29,$29,4 jr $31 ; remove cursor rmcrs: add $8,$0,scrptr ldw $8,$8,0 add $9,$0,scrchr ldw $10,$9,0 stw $10,$8,0 jr $31 ; set cursor stcrs: add $8,$0,scrptr ldw $8,$8,0 add $9,$0,scrchr ldw $10,$8,0 stw $10,$9,0 add $10,$0,(0x87 << 8) | '_' stw $10,$8,0 jr $31 ; calculate screen pointer based on row and column calcp: add $9,$0,dspbase add $8,$0,scrrow ldw $10,$8,0 sll $10,$10,7+2 add $9,$9,$10 add $8,$0,scrcol ldw $10,$8,0 sll $10,$10,0+2 add $9,$9,$10 add $8,$0,scrptr stw $9,$8,0 jr $31 ; clear screen clrscr: add $11,$0,(0x07 << 8) | ' ' add $8,$0,dspbase add $9,$0,30 clrscr1: add $10,$0,80 clrscr2: stw $11,$8,0 add $8,$8,4 sub $10,$10,1 bne $10,$0,clrscr2 add $8,$8,(128-80)*4 sub $9,$9,1 bne $9,$0,clrscr1 jr $31 ; scroll screen scrscr: add $8,$0,dspbase add $9,$0,29 scrscr1: add $10,$0,80 scrscr2: ldw $11,$8,128*4 stw $11,$8,0 add $8,$8,4 sub $10,$10,1 bne $10,$0,scrscr2 add $8,$8,(128-80)*4 sub $9,$9,1 bne $9,$0,scrscr1 add $11,$0,(0x07 << 8) | ' ' add $10,$0,80 scrscr3: stw $11,$8,0 add $8,$8,4 sub $10,$10,1 bne $10,$0,scrscr3 jr $31 ;*************************************************************** .bss .align 4 scrptr: .word 0 scrrow: .word 0 scrcol: .word 0 scrchr: .word 0
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