A. Board Configuration
ÛZIATECH
97
CT16, CT17, CT25, CT29, CT39 (Frontplane DMA Channel Selection)
The ZT 8907 supports either 8-bit or 16-bit frontplane DMA, available on connector J6.
Up to three frontplane DMA channels are available simultaneously. These cuttable
traces configure the three chosen frontplane DMA channels to be either 8-bit or 16-bit.
Be sure to mask unused channels not required by the application. Refer to Chapter 6,
"
," for more information.
Default Frontplane DMA Settings
Channel
Selection
Cuttable Trace
Data
Size
Available on J6...
DMA channel 0
CT39B
8-bit
pins 1 (DRQ) and 3 (DAK)
†
DMA channel 1
CT29B
8-bit
pins 2 (DRQ) and 4 (DAK)
†
DMA channel 7
CT16A, CT17A, CT25B
16-bit
pins 5 (DRQ) and 7 (DAK)
Alternate Frontplane DMA Settings
Channel
Selection
Cuttable Trace
Data
Size
Available on J6...
DMA channel 5
CT39A
16-bit
pins 1 (DRQ) and 3 (DAK)
DMA channel 6
CT29A
16-bit
pins 2 (DRQ) and 4 (DAK)
DMA channel 3
CT16B, CT17B, CT25A
8-bit
pins 5 (DRQ) and 7 (DAK)
CT46, CT47 (Board Revision)
These cuttable traces are set at the factory depending on the current board revision and
should not be modified by the user.
CT48 (INTRQ4* STD Connection)
Configuring CT48 selects the function of pin P5 on the STD 32 connector. By default
(CT48 = In), the ZT 8907 uses pin P5 for signal INTRQ4*.
†
Factory default configuration
‡
By default, DMA channel 3 is assigned to the on-board parallel printer port. Route DMA channel 3 to
connector J6 by configuring CT16, CT17, and CT25 as shown above.