mirror of
https://github.com/EranMorkon/AMTS.git
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67 lines
3.2 KiB
ArmAsm
67 lines
3.2 KiB
ArmAsm
;******************************************************************************
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;* Z80 Assembler program *
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;* Josef Reisinger *
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;* josef.reisinger@htl-hl.ac.at *
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;* 10/07/2017 *
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;******************************************************************************
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; ---------------------------- PIO 82C55 I/O ---------------------------------
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PIO_A: EQU $80 ; (INPUT)
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PIO_B: EQU $81 ; (OUTPUT) OUT TO LEDS
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PIO_C: EQU $82 ; (INPUT) IN from DIP SWITCHES
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PIO_CON: EQU $83 ; CONTROL BYTE PIO 82C55
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; --------------------------- CTC Z80 Timer Counter --------------------------
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CTC0 EQU $00 ; Channel 0
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CTC1 EQU $01 ; Channel 1
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CTC2 EQU $02 ; Channel 2
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CTC3 EQU $03 ; Channel 3
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; -------------------------- SIO (USART) ----------------------------------------
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SIO_A_D: EQU $40 ; Channel A Data Register
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SIO_B_D: EQU $41 ; Channel B Data Register
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SIO_A_C: EQU $42 ; Channel A Control Register
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SIO_B_C: EQU $43 ; Channel B Control Register
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;-------------------------- CONSTANTS ----------------------------------------
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RAMTOP: EQU $FFFF ; 32Kb RAM 8000H-FFFFH
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COUNTER: EQU $8000 ; RAM Counter
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;******************************************************************************
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;* RESET HANDLER *
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;* Function: Initialize system and start Main Program *
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;******************************************************************************
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ORG $0000
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DI ; Disable interrupt
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LD SP,RAMTOP ; Set stack pointer
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JP MAIN ; jump to Main program
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;*******************************************************************
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;* MAIN PROGRAM *
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;*******************************************************************
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ORG $100
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MAIN: LD A,$99 ; Initialize 8255: PA0-PA7=IN (DIP SWITCHES), PB0-PB7=OUT (LEDS),
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OUT (PIO_CON),A ; PC0-PC7=IN, Mode 0 Selection
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LD A,$01 ; Initialize RAM Counter
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LD HL,COUNTER ; Load RAM Counter Address
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LD (HL),A ; Store Counter in RAM cell
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AGAIN: LD A,(HL) ; Load RAM Counter
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OUT (PIO_B),A ; Output RAM Counter to LEDs (PB0-PB7)
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INC (HL) ; Increment RAM Counter
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CALL _WAIT ; UP Warteschleife aufrufen
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JP AGAIN ; Endlos
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;*******************************************************************
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;* Warteschleife 0,5s *
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;*******************************************************************
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_WAIT: LD D,$FF ;
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_OUTER: LD E,$FF ;
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_INNER: DEC E
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JP NZ,_INNER
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DEC D
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JP NZ,_OUTER
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RET |