; -*-asm-*-
include(`common.m4')

        BRA r :reset ; RESB
        BRA r :irq   ; IRQB

irq:    PHA s
        LDA a %10000000
        STA a IFR
        PLA s
        RTI s

        ;; reset stack
reset:  LDX # ff
        TXS i

        ;;     xxxSSSxx
        LDA # hh(ACR_SR_OUT_PHI2)
        STA a ACR

        LDA # %10000000
        STA a PORTA

        LDA # %10000000
        STA a DDRA

        LDA # %01111111
        STA a IER

        LDA # %10000100
        STA a IER

        ;;   R   T FEN SHD  TM  RM  PM RAM
        ;;   1   1   1   0   0   0   0   0
        LDX # %11100000         ; write configuration
        ;; IR ST PE  L B3 B2 B1 B0
        ;;  0  0  0  0  0  0  0  1 ; 115200
        LDY # %00000001
        JSR a :spi16

        ;;   R   T FEN SHD  TM  RM  PM RAM
        ;;   1   1   1   0   0   0   0   0
        LDX # %11100000         ; write configuration
        ;; IR ST PE  L B3 B2 B1 B0
        ;;  0  0  0  0  0  0  0  1 ; 115200
        LDY # %00000001
        JSR a :spi16

        ;;   R   T FEN SHD  TM  RM  PM RAM
        ;;   1   1   1   0   0   0   0   0
        LDX # %01000000         ; read configuration
        ;; IR ST PE  L B3 B2 B1 B0
        ;;  0  0  0  0  0  0  0  1 ; 115200
        LDY # %00000000
        JSR a :spi16

        ;;   R   T FEN SHD  TM  RM  PM RAM
        ;;   1   1   1   0   0   0   0   0
        LDX # %01000000         ; read configuration
        ;; IR ST PE  L B3 B2 B1 B0
        ;;  0  0  0  0  0  0  0  1 ; 115200
        LDY # %00000000
        JSR a :spi16

        LDX # %00000000         ; read data
        LDY # %00000000
        JSR a :spi16

        LDX # %10000000         ; write data
        LDY # ca
        JSR a :spi16

        LDX # %10000010         ; write data
        LDY # ca
        JSR a :spi16


forever:        BRA r :forever

spi16:  CLI i

        LDA # %00000000
        STA a PORTA

        STX a SR
        WAI i
        STY a SR
        WAI i

        LDA # %10000000
        STA a PORTA

        SEI i

        RTS s