Z80180/Z8S180/Z8L180
Enhanced Z180 Microprocessor
Zilog
DMA I/O ADDRESS REGISTER CHANNEL 1
(IAR1: I/O Address = 2BH to 2DH) specifies the I/O ad-
dress for channel 1 transfers. This may be destination or
source I/O address. The register contains 16 bits of I/O ad-
dress; its most significant byte identifies the Request
Handshake signal and controls the Alternating Channel
feature.
All bits in IAR1B reset to 0.
Bit
7
6
5
4
3
2
1
0
A/T
F
A/T
C
TOUT
/DREQ
Req 1 Sel
Figure 68. IAR MS Byte Register (IARIB: I/O Address 2DH)
DMA I/O Address Register Channel 1L
DMA I/O Address Register Channel 1B
Mnemonic IAR1L
Mnemonic IAR1B
Address 2B
Address 2D
Figure 69. DMA I/O Address Register Channel 1L
Figure 71. DMA I/O Address Register Channel 1B
DMA I/O Address Register Channel 1H
Mnemonic IAR1H
Address 2C
Figure 70. DMA I/O Address Register Channel 1H
1-54
P R E L I M I N A R Y
DS971800401
ZILOG [ ZILOG, INC. ]
