Expansion Interfaces
EPM-31 Hardware Reference Manual
56
Most PC/104-
Plus
(PCI +ISA) or PC/104 (ISA only) expansion modules will work, but be sure to
check the requirements of your PC/104 card against the list above.
ISA
I/O
S
UPPORT
Both 8-bit and 16-bit I/O cycles are supported, but for 16-bit cycles the PC/104 (ISA) module
must be 16-bit capable and must assert IOCS16#.
Table 18 lists the I/O ranges available on the ISA bus unless there is a device claiming the range
on the LPC or PCI bus. The FPGA on the EPM-31 uses I/O addresses 0xC80-0xCBF and, if
enabled, the FPGA has two COM ports that can be configured in the BIOS Setup utility to map
to various address ranges.
By default, the two COM ports in the FPGA are enabled and occupy the I/O address ranges of
0x3F8-0x3FF and 0x2F8-0x2FF. The following are the I/O address ranges available on the ISA
bus when the BIOS is configured to factory defaults.
Table 18: Available ISA Bus I/O Ranges
0x0 – 0x1F
0x3E – 0x3F
0x93 – 0x9F
0x300 – 0x3AF
0x22 – 0x23
0x43 – 0x4F
0xA2 – 0xA3
0x3BC – 0x3BF
0x26 – 0x27
0x53 – 0x5F
0xA6 – 0xA7
0x3E0 – 0x3F7
0x2A – 0x2B
0x62
0xAA – 0xAB
0x480 – 0x4CF
0x2E – 0x2F
0x66
0xAE – 0xAF
0x4D2 – 0x4FF
0x32 – 0x33
0x68 – 0x70
0xB6 – 0xB7
0x600 – 0xC7F
0x36 – 0x37
0x78 – 0x7F
0xBA – 0xBB
0xCC0 – 0xCF8
0x3A – 0x3B
0x90 – 0x91
0xBE – 0x2F7
0xCFA – 0xCFB
0xD00 – 0xFFF
Assuming the COM ports in the FPGA are disabled, the available I/O base addresses for COM
ports on the ISA bus are as follows:
0x200
0x228
0x338
0x208
0x238
0x3E8
0x220
0x2E8
0x3F8
Each COM port in the FPGA that is enabled will use one of these I/O base addresses and, in that
case, that 8 byte I/O range will not be available on the ISA bus. PCI devices may be assigned I/O
space, but that usually occurs at I/O address 0x1000 or higher so as to not conflict with legacy
I/O devices.
ISA
M
EMORY
S
UPPORT
The following memory addresses are available on the ISA bus:
0xA0000 – 0xB7FFF