Ampro Corporation Littleboard 550 IRQ15, IRQ14, DACK0, DRQ0, DACK5, DRQ5, DACK6, DRQ6, DACK7

Chapter 3 Hardware

Pin #		Signal	Descriptions (J1 Row D)
27	(D6)	IRQ15	Interrupt Request 15 – Asserted by a device when it has pending interrupt
			request. Only one device may use the request line at a time.
28	(D7)	IRQ14	Interrupt Request 14 – Asserted by a device when it has pending interrupt
			request. Only one device may use the request line at a time.
29	(D8)	DACK0*	DMA Acknowledge 0 – Used by DMA controller to select the I/O
			resource requesting the bus, or to request ownership of the bus as a bus
			master device. Can also be used by the ISA bus master to gain control of
			the bus from the DMA controller.
30	(D9)	DRQ0	DMA Request 0 – Used by I/O resources to request DMA service. Must
			be held high until associated DACK0 line is active.
31	(D10)	DACK5*	DMA Acknowledge 5 – Used by DMA controller to select the I/O
			resource requesting the bus, or to request ownership of the bus as a bus
			master device. Can also be used by the ISA bus master to gain control of
			the bus from the DMA controller.
32	(D11)	DRQ5	DMA Request 5 – Used by I/O resources to request DMA service. Must
			be held high until associated DACK5 line is active.
33	(D12)	DACK6*	DMA Acknowledge 6 – Used by DMA controller to select the I/O
			resource requesting the bus, or to request ownership of the bus as a bus
			master device. Can also be used by the ISA bus master to gain control of
			the bus from the DMA controller.
34	(D13)	DRQ6	DMA Request 6 – Used by I/O resources to request DMA service. Must
			be held high until associated DACK6 line is active.
35	(D14)	DACK7*	DMA Acknowledge 7 – Used by DMA controller to select the I/O
			resource requesting the bus, or to request ownership of the bus as a bus
			master device. Can also be used by the ISA bus master to gain control of
			the bus from the DMA controller.
36	(D15)	DRQ7	DMA Request 7 – Used by I/O resources to request DMA service. Must
			be held high until associated DACK7 line is active.
37	(D16)	+5V	+5 volt power ±10%
38	(D17)	MASTER*	Bus Master Assert – This signal is used by an ISA board along with a
			DRQ line to gain ownership of the ISA bus. Upon receiving a -DACK a
			device can pull -MASTER low which will allow it to control the system
			address, data, and control lines. After -MASTER is low, the device
			should wait one CLK period before driving the address and data lines,
			and two clock periods before issuing a read or write command.
39	(D18)	GND	Ground
40	(D19)	GND	Ground

Notes: The shaded area denotes power or ground. The signals marked with * = Negative true logic.

34 Reference Manual LittleBoard 550