Z80189 Datasheet, PDF (55/107 Pages) Zilog, Inc. – GENERAL-PURPOSE EMBEDDED CONTROLLERS

Zilog
IAR1L
Read/Write
IA7
IAR1H
Read/Write
IA15
PRELIMINARY
Z80189/Z8L189
GENERAL-PURPOSE EMBEDDED CONTROLLERS
Addr 2BH
IA0
BCR1L
Read/Write
BC7
Addr 2EH
BC0
Addr 2CH
IA8
BCR1H
Read/Write
BC15
Addr 2FH
BC8
Figure 62. DMA I/O Address Registers
Figure 63. DMA 1 Byte Count Registers
IAR1B
Addr 2D
D7 D6 D5 D4 D3 D2 D1 D0
New Z8S180 Register
000 = DMA1 ext TOUT/DREQ
001 = DMA1 ASCI0
010 = DMA1 ASCI1
011 = DMA1 ext CKA0//DREQ0
111 = Reserved, do not program
Reserved, program as 0.
Currently selected DMA
Channel when Bit 7 = 1
Alternating Channels
0 = DMA Channels
are independent
1 = Toggle between DMA
channels for same device
Figure 64. DMA I/O Address Register Ch. 1
DS971890301
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