Interfaces and Connectors
EPM-5 Reference Manual
38
PC/104 Expansion Bus
EPM-5 has limited support of the PC/104 bus. Most PC/104 cards will work, but be sure to check
the requirements of your PC/104 card against the list below.
PC/104
I/O
S
UPPORT
The following I/O ranges are supported:
100h – 1CFh
1D3h – 1D9h
1DBh – 1EFh
200h – 36Fh (2E8h–2EF excluded if COM4 is enabled)
3E8h – 3EF (range excluded if COM3 is enabled)
3F7h – 47Fh (3F8h–3FF excluded if COM1 is enabled)
490h – 4CFh
4D2h – 777h
77Ch – AFFh
Note:
Rev 5.01 boards and later support 16-bit I/O transfers. On Rev 5.00 and earlier
boards, all 16-bit I/O reads and writes were converted into two 8-bit cycles (low
byte, then high byte) on the PC/104 bus. The PLD code that enables 16-bit
transfers can be installed on Rev 5.00 boards. See KnowledgeBase article
VT1477
PLD and BIOS 5.3.104 Update Instructions
. Later PLD updates are also available.
To access them, search the
VersaTech KnowledgeBase
on the keywords “EPM-5
PLD.”
PC/104
M
EMORY
S
UPPORT
Memory ranges supported:
CC000h-DBFFFh, 8-bit transfers only
IRQ
S
UPPORT
The following IRQs are available on the PC/104 bus:
IRQ 3, IRQ 4, IRQ 10
Each of the three IRQs must be enabled in CMOS Setup before they can be used on the ISA bus.
Because ISA IRQ sharing is not supported, make sure that any IRQ channel used for an ISA
device is not used elsewhere. For example, if ISA IRQ 4 is enabled, you must use a different IRQ
for COM1.
DMA
S
UPPORT
The current revision of the board does not support PC/104 DMA.
