Z85233 Datasheet, PDF (191/317 Pages) Zilog, Inc. – The Zilog SCC Serial Communication Controller

Application Note
The Z180™ Interfaced with the SCC at MHZ
(Continued)
Table 14. Test Program – Z180/SCC DMA Transfer (Continued)
db
01h
db
11100000b
;select WR1
;enable DMA
db
0fh
db
00000000b
db
10h
db
10h
;select WR15
;don’t use any of ext/stat int
;reset ext/stat twice
db
01h
db
11100000b
;select WR1
;no int
db
09h
db
00001001b
;select WR9
;enable int
db
0ffh
;end of table
;source/dist addr table for Z180’s dma
addrtab:
db
scc_data
db
00h
db
00h
;dmac0 source
dw
rx_buff
db
00h
;dmac0 dist
dw
length
;byte count
dw
tx_buff+1
db
00h
;mar
db
scc_data
;iar
db
00h
db
00h
;dummy!
dw
length-1
;byte count
;interrupt vector table
z180vect:
org
.block
.block
.block
.block
dw
dw
.block
.block
.block
sccdma + 200h
2
2
2
2
rxend
txend
2
2
2
;180 int1 vect 00000
;180 int2 vect 00010
;180 prt0 vect 00100
;180 prt1 vect 00110
;180 dmac0 vect 01000
;180 dmac1 vect 01010
;180 csi/o vect 01100
;180 asci0 vect 01110
;180 asci1 vect 10000
tx_buff:
rx_buff:
temp:
org
.block
.block
.block
sccdma + 1000h
length
length
1
end
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