Dma Channel Assignments; Table 1-3. Dreq Line Assignments - Dell OptiPlex GXa Service Manual

Dell OptiPlex GXa Systems Service Manual
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Table 1-2. Interrupt Assignments (continued)
IRQ Line Used By/Available
IRQ8 Generated by keyboard controller for each tick of RTC.
IRQ9 Available for use by an expansion card.
IRQ10 Available for use by an expansion card.
IRQ11 Available for use by an expansion card.
IRQ12 Generated by keyboard controller to indicate that mouse's output
buffer is full.
IRQ13 Generated by math coprocessor to indicate coprocessor error.
IRQ14 Generated by device connected to primary EIDE port to indicate
that device requires service. If the EIDE controller is disabled,
this line is available for other use.
IRQ15 Generated by device connected to secondary EIDE port to
indicate that device requires service. If the EIDE controller is
disabled, this line is available for other use.
NOTE: The built-in sound controller and built-in NIC controller are assigned available
IRQs automatically during system start-up.

DMA Channel Assignments

Table 1-3. DREQ Line Assignments

DREQ Line Used By/Available
DREQ0 Available
DREQ1 Available
DREQ2 Generated by super I/O controller to initiate DMA cycle for
attached diskette drive
DREQ3 Available
DREQ4 Generated by bus controller chip to activate second DMA
controller
DREQ5 Available
DREQ6 Available
DREQ7 Available
NOTE: The built-in sound controller, built-in NIC, and built-in video controllers are assigned
available DMA channels automatically during system start-up.