Toshiba T3200 User Manual page 159

B • 4
DNA MEMORY ADDRESS
DMA page address is stored in the DMA page address register
in the Memory Mapper GA before it is used in the DMA cycle.
The DMA page address register has 8 bit length and it is
output to the address lines A23 - Al7 and PGAl6 during the
DMA cycle.
Each DMA channel has a DMA page address register and address
is assigned as follows.
TABLE B-2 Address Assignment of DMA Address Register
Adress Channel DMA
081H Channel 2 Slave DMA
082H Channel 3
II
087H Channel 0
II
089H
Channel 6 Master DMA
08AH Channel7
II
08FH
*
Refresh
II
To store the DMA page address, the address lines XA are
decoded and the data on the XD lines are stored in the
selected register.
CPU
>
<
XD7
.l(nn
Interface
8bit x 16
CPu
commands
Latch
I<=- A23
Register
(SA9)
I - - -
I
XA8 XAO
>
Address f - -
>
Select
I
DACK7 DACKO
>
FIGURE B-2 DMA Page Address Register
B-9
A16
>