Technical Reference Guide
Compaq Deskpro EXS and Workstation 300 Personal Computers
Featuring the Intel Pentium 4 Processor
First Edition - December 2000
5-3
5.2.2 IDE
CONNECTOR
This system uses a standard 40-pin connector for the primary IDE device and connects (via a
cable) to the hard drive installed in the right side drive bay. Note that some signals are re-defined
for UATA/33 and UATA/66 modes, which require a special 80-conductor cable (supplied)
designed to reduce cross-talk. Device power is supplied through a separate connector.
Figure 5-1.
40-Pin Primary IDE Connector (on system board).
Table 5–3
. 40-Pin Primary IDE Connector Pinout
Table 5-3.
40-Pin Primary IDE Connector Pinout
Pin
Signal
Description
Pin
Signal
Description
1
RESET-
Reset
21
DRQ
DMA Request
2
GND
Ground
22
GND
Ground
3
DD7
Data Bit <7>
23
IOW-
I/O Write [1]
4
DD8
Data Bit <8>
24
GND
Ground
5
DD6
Data Bit <6>
25
IOR-
I/O Read [2]
6
DD9
Data Bit <9>
26
GND
Ground
7
DD5
Data Bit <5>
27
IORDY
I/O Channel Ready [3]
8
DD10
Data Bit <10>
28
CSEL
Cable Select
9
DD4
Data Bit <4>
29
DAK-
DMA Acknowledge
10
DD11
Data Bit <11>
30
GND
Ground
11
DD3
Data Bit <3>
31
IRQn
Interrupt Request [4]
12
DD12
Data Bit <12>
32
IO16-
16-bit I/O
13
DD2
Data Bit <2>
33
DA1
Address 1
14
DD13
Data Bit <13>
34
DSKPDIAG
Pass Diagnostics
15
DD1
Data Bit <1>
35
DA0
Address 0
16
DD14
Data Bit <14>
36
DA2
Address 2
17
DD0
Data Bit <0>
37
CS0-
Chip Select
18
DD15
Data Bit <15>
38
CS1-
Chip Select
19
GND
Ground
39
HDACTIVE-
Drive Active (front panel LED) [5]
20
--
Key
40
GND
Ground
NOTES:
[1] On UATA/33 and higher modes, re-defined as STOP.
[2] On UATA/33 and higher mode reads, re-defined as DMARDY-.
On UATA/33 and higher mode writes, re-defined as STROBE.
[3] On UATA/33 and higher mode reads, re-defined as STROBE-.
On UATA/33 and higher mode writes, re-defined as DMARDY-.
[4] Primary connector wired to IRQ14, secondary connector wired to IRQ15.
[5] Pin 39 is used for spindle sync and drive activity (becomes SPSYNC/DACT-)
when synchronous drives are connected.
