Chapter 3

 

Hardware

 

 

 

 

 

 

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.

ReadyBoard 700

Reference Manual

29

Page 35
Image 35
Ampro Corporation 700 manual Pin # Signal Descriptions J13 Row B