TME-EPIC-HURLX-R3V5.docx
Rev 3.5
Page 28 of 49
3.20
PC/104 Bus Interface (J21)
The PC/104 bus is a modification of the industry standard (ISA) PC bus specified in IEEE P996. The PC/104 bus
has different mechanics than P966 to allow the stacking of modules. The main features are:
•
Supports programmable extra wait state for ISA cycles
•
Supports I/O recovery time for back-to-back I/O cycles
Pin
1
IOCHCK#
GND
2
D7
RSTDRV
3
D6
+5V
see note
4
D5
IRQ9
5
D4
-5V
6
D3
DRQ2
7
D2
-12V
see note
Pin
D
C
8
D1
ENDXFER
0
GND
GND
9
D0
+12V
1
MEMCS16#
SBHE#
10
IOCHRDY
KEY
2
IOCS16#
LA23
11
AEN
SMEMW#
3
IRQ10
LA22
12
A19
SMEMR#
4
IRQ11
LA21
13
A18
IOW#
5
IRQ12
LA20
14
A17
IOR#
6
IRQ15
LA19
15
A16
DACK3#
7
IRQ14
LA18
16
A15
DRQ3
8
DACK0#
LA17
17
A14
DACK1#
9
DRQ0
MEMR#
18
A13
DRQ1
10
DACK5#
MEMW#
19
A12
REFRESH#
11
DRQ5
SD8
20
A11
SYSCLK
12
DACK6#
SD9
21
A10
IRQ7
13
DRQ6
SD10
22
A9
IRQ6
14
DACK7#
SD11
23
A8
IRQ5
15
DRQ7
SD12
24
A7
IRQ4
16
+5V
SD13
25
A6
IRQ3
17
MASTER#
SD14
26
A5
DACK2#
18
GND
SD15
27
A4
TC
19
GND
GND
28
A3
BALE
29
A2
+5V
30
A1
OSC
31
A0
GND
32
GND
GND
+3.3V, +12V and –12V are only routed to connectors for external I/O extension. Their current is limited to 1A each.
