Chapter 3

 

Hardware

 

 

 

 

 

 

Pin #

Signal

Description (P1 Row D)

 

 

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

+5V 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 * indicate active low.

26

Reference Manual

CoreModule 420

Page 32
Image 32
Ampro Corporation 5001692A manual DRQ5, DRQ6, DRQ7