Chapter 3

 

Hardware

 

 

 

 

 

Pin #

Signal

Description

 

25

PIOR*

Drive I/O Read – Strobe signal for read functions. Negative edge enables data

 

 

 

from a register or data port of the drive onto the host data bus. Positive edge

 

 

 

latches data at the host.

 

26

GND

Digital Ground

 

27

IOChRdy

I/O Channel Ready – When negated, extends the host transfer cycle of any host

 

 

 

register access when the drive is not ready to respond to a data transfer request.

 

 

 

High impedance if asserted.

 

28

Reserved

Reserved – Not used (through 470 ohm resistor to ground)

 

 

 

 

 

29

PDACK*

DMA Channel Acknowledge – Used by the host to acknowledge data has been

 

 

 

accepted or data is available. Used in response to DMARQ asserted.

 

30

GND

Digital Ground

 

31

PIRQ

Interrupt Request – Asserted (IRQ 14) by drive when it has pending interrupt

 

 

 

request (PIO transfer of data to or from the drive to the host).

 

32

NC

Not connected

 

 

 

 

 

33

LA18

Latch Address 18 – Used to indicate which byte in the ATA command block or

 

 

 

control block is being accessed.

 

34

NC

Not connected (through 0.047 ∝ f capacitor to ground)

 

 

 

 

 

35

LA17

Latch Address 17 – Used to indicate which byte in the ATA command block or

 

 

 

control block is being accessed.

 

36

LA19

Latch Address 19 – Used to indicate which byte in the ATA command block or

 

 

 

control block is being accessed

 

37

IDE_PCS1

IDE Chip Select 1 – Used to select the host-accessible Command Block Register.

 

 

 

 

 

38

IDE_PCS3

IDE Chip Select 3 – Used to select the host-accessible Command Block Register.

 

 

 

 

 

39

Reserved

Reserved – Not used

 

 

 

 

 

40

GND

Digital Ground

 

41

+5V

+5 volts ±5% power supply

 

42

+5V

+5 volts ±5% power supply

 

43

GND

Digital Ground

 

44

NC

Not connected

 

 

 

 

Notes: The shaded area denotes power or ground. The signals marked with * indicate active low.

28

Reference Manual

CoreModule 420

Page 34
Image 34
Ampro Corporation 5001692A manual Pior, Pdack, Pirq, IDEPCS1, IDEPCS3