db 01h ;select WR1
db 11100000b ;enable DMA
db 0fh ;select WR15
db 00000000b ;don’t use any of ext/stat int
db 10h ;reset ext/stat twice
db 10h
db 01h ;select WR1
db 11100000b ;no int
db 09h ;select WR9
db 00001001b ;enable int
db 0ffh ;end of table
;source/dist addr table for Z180’s dma
addrtab: db scc_data ;dmac0 source
db 00h
db 00h
dw rx_buff ;dmac0 dist
db 00h
dw length ;byte count
dw tx_buff+1 ;mar
db 00h
db scc_data ;iar
db 00h
db 00h ;dummy!
dw length-1 ;byte count
;interrupt vector table
org sccdma + 200h
z180vect: .block 2 ;180 int1 vect 00000
.block 2 ;180 int2 vect 00010
.block 2 ;180 prt0 vect 00100
.block 2 ;180 prt1 vect 00110
dw rxend ;180 dmac0 vect 01000
dw txend ;180 dmac1 vect 01010
.block 2 ;180 csi/o vect 01100
.block 2 ;180 asci0 vect 01110
.block 2 ;180 asci1 vect 10000
org sccdma + 1000h
tx_buff: .block length
rx_buff: .block length
temp: .block 1
end
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