8237 Dma Controllers - Teknor Industrial Computers TEK-AT4LVG Technical Reference Manual

The ISA Bus Interface on the TEK-AT4LVG board integrates the functionality of two
8237 DMA Controllers (see Table 7-8), two interrupt controllers (see Table 7-9) and one
8254 Counter/Timer.
TABLE 7-8: 8237 DMA Controllers
DMA 0 Available
DMA 1 Available (ECP)
DMA 2 Floppy controller
DMA 3 Available (ECP)
DMA 4 Cascade controller # 1
DMA 5 Available
DMA 6 Available
DMA 7 Available
The parallel port's ECP mode can be configured to use DMA Channel 1 or 3. Channel 2 is
reserved for the Floppy controller and Channel 4 is used to cascade Channels 0 through 7
to the microprocessor.
TABLE 7-9: 8259 Interrupt Controllers
Controller # 1
IRQ 0 Timer 0
IRQ 1 Keyboard
IRQ 2 Cascade controller # 2
IRQ 3 COM 2 *
IRQ 4 COM 1 *
IRQ 5 Available (LPT2)*
IRQ 6 Floppy controller *
IRQ 7 LPT1*
* All functions marked with an asterisk (*) can be disabled or reconfigured.
Installing and Working With System Components
Controller # 2
IRQ 8 Real-time clock
IRQ 9 Available
IRQ 10 Available or SCSI
IRQ 11 Available or SCSI
IRQ 12 PS/2 Mouse Interface
IRQ 13 Coprocessor Error
IRQ 14 Primary IDE * or available
IRQ 15 Secondary IDE * or available
7-18