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Ampro Corporation Single Board Computer 700 User Manual

Page 35

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Chapter 3

Hardware

ReadyBoard 700

Reference Manual

29

Pin #

Signal

Description (J13 Row A)

25 (A25)

SA6

System Address 6 – Refer to SA19, pin-A12, for more information.

26 (A26)

SA5

System Address 5 – Refer to SA19, pin-A12, for more information.

27 (A27)

SA4

System Address 4 – Refer to SA19, pin-A12, for more information.

28 (A28)

SA3

System Address 3 – Refer to SA19, pin-A12, for more information.

29 (A29)

SA2

System Address 2 – Refer to SA19, pin-A12, for more information.

30 (A30)

SA1

System Address 1 – Refer to SA19, pin-A12, for more information.

31 (A31)

SA0

System Address 0 – Refer to SA19, pin-A12, for more information.

32 (A32)

GND

Ground

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

Table 3-6. PC/104 Interface Pin/Signal Descriptions (J13B)

Pin #

Signal

Descriptions (J13 Row B)

33 (B1)

GND

Ground

34 (B2)

RESETDRV

Reset Drive – This signal is used to reset or initialize system logic on
power up or subsequent system reset.

35 (B3)

+5V

+5 volt power ±10%

36 (B4)

IRQ9

Interrupt request 9 – Asserted by a device when it has pending interrupt
request. Only one device may use the request line at a time.

37 (B5)

-5V

Not connected (-5 volts)

38 (B6)

DRQ2

DMA Request 2 – Used by I/O resources to request DMA service, or to
request ownership of the bus as a bus master device. Must be held high
until associated DACK2 line is active.

39 (B7)

-12V

Not connected (-12 volts)

40 (B8)

ENDXFR*

Zero Wait State – This signal is driven low by a bus slave device to
indicate it is capable of performing a bus cycle without inserting any
additional wait states. To perform a 16-bit memory cycle without wait
states, this signal is derived from an address decode.

41 (B9)

+12V

+12 Volts

42 (B10)

GND

Not connected (Key Pin)

43 (B11)

SMEMW*

System Memory Write – This signal is used by bus owner to request a
memory device to store data currently on the data bus and only active
for the lower 1MB. Used for legacy compatibility with 8-bit cards.

44 (B12)

SMEMR*

System Memory Read – This signal is used by bus owner to request a
memory device to drive data onto the data bus and only active for lower
1MB. Used for legacy compatibility with 8-bit cards.

45 (B13)

IOW*

I/O Write – This strobe signal is driven by the owner of the bus (ISA
bus master or DMA controller) and instructs the selected I/O device to
capture the write data on the data bus.

46 (B14)

IOR*

I/O Read – This strobe signal is driven by the owner of the bus (ISA bus
master or DMA controller) and instructs the selected I/O device to drive
read data onto the data bus.

47 (B15)

DACK3*

DMA Acknowledge 3 – 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.