jens
dd51f49d5b
git-svn-id: http://moon:8086/svn/vhdl/trunk@1634 cc03376c-175c-47c8-b038-4cd826a8556b
59 lines
1.3 KiB
JavaScript
59 lines
1.3 KiB
JavaScript
; -------------------------------------------------
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; uart.inc.jsm
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; -------------------------------------------------
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; needs xmem-address definition for
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; - uart_status (Status register)
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; - uart_data (Data register)
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UART_TX_EMPTY: equ 0x01
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UART_TX_FULL: equ 0x02
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UART_TX_CMPL: equ 0x04
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UART_RX_PRESENT: equ 0x10
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; -------------------------------------------------
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; uart_puts
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; -------------------------------------------------
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; R1 : ptr to string
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uart_puts: push R0
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u_p_lp: movx R0, (R1)
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inc R1
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tst R0
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jz ex_ugp
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call uart_putchar
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jmp u_p_lp
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ex_ugp: pop R0
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ret
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; -------------------------------------------------
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; uart_putchar
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; -------------------------------------------------
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; R0 = input
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uart_putchar: jmp sout
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; -------------------------------------------------
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; sout
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; -------------------------------------------------
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; R0 = input
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sout: push R1
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sout1: xin R1, (uart_status)
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and R1, UART_TX_FULL
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jnz sout1
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xout (uart_data), R0
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pop R1
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ret
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; -------------------------------------------------
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; sin
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; -------------------------------------------------
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; R0 = output
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sin: push R1
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sin1: xin R1, (uart_status)
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and R1, UART_RX_PRESENT
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jnz sin1
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xin R0, (uart_data)
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pop R1
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ret
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; -------------------------------------------------
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