e73d8db74c
Fixes a typo with getc_nb, removes the RTC tick code (since we know it works now and it is clogging up the screen), read characters in a loop instead of just once.
94 lines
2.1 KiB
ArmAsm
94 lines
2.1 KiB
ArmAsm
.MACPACK generic
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.autoimport
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.import _enable_irq, _send_eoi, _uart_txb_block
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.importzp tmp1, ptr1
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.export _serial_init
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.export _serial_handle_irq
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.export _serial_putc, _serial_puts, _serial_getc, _serial_getc_nb
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.zeropage
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last_char: .res 1
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.code
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UART = $efe6
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UART_TXB = UART
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UART_RXB = UART
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UART_STATUS = UART + 1
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; Initialize Serial Port
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; No initialization needed, just register irq handler.
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.proc _serial_init
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lda #<_serial_handle_irq
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ldx #>_serial_handle_irq
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jsr pushax
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lda #$01
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jsr _register_irq
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stz last_char
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rts
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.endproc
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; Serial Port IRQ Handler
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; Get the character and store it.
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.proc _serial_handle_irq
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lda UART_RXB
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ora #$80 ; set msb
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sta last_char
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jsr _send_eoi
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rti
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.endproc
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; Serial Port Get Character
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; If a character has not been received, block until one is.
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.proc _serial_getc
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L1: lda last_char
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bpl L1
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and #$7f
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sta last_char
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rts
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.endproc
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; Serial Port Get Character Non-Blocking
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; return last character, even if it has already been read.
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; If the character is new, we still clear the new flag.
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.proc _serial_getc_nb
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lda last_char
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bpl L1
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and #$7f
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sta last_char
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L1: rts
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.endproc
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; Serial Port Put Character
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; send a single character over the serial port.
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.proc _serial_putc
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jsr _uart_txb_block
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cmp #$0a
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bne @1
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lda #$0d
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jsr _uart_txb_block
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@1: rts
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.endproc
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; Send a string over the serial port. Needs stlen
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.proc _serial_puts
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sta ptr1 ; Store pointer in ptr1
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stx ptr1+1
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ldy #$00 ; initialize y to 0
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L1: lda (ptr1),y ; load character from string
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beq L2 ; Quit if NULL
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jsr _uart_txb_block ; send character (does not change y or ptr1)
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iny ; increment y
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bne L1 ; If Y == 0, increment high byte of pointer
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inc ptr1+1
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bne L1 ; if high byte wraps around, give up
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L2: rts
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.endproc |