Xycom XVME-976, Manual

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XVME-976 Adapter Module
2-4
Within a given jumper group, the individual jumpers set the values of indi-
vidual I/O base address bits, as shown in Table 2-6. Shorting a particular
jumper pin pair sets the corresponding address bit to 0.
Table 2-6. I/O Address Selection Jumper Pins
Pair
Shorted
1/2 3/4 5/6 7/8 9/10 11/12 13/4
Bit Cleared
A9 A8 A7 A6 A5 A4 A3
As the table indicates, the jumpers set values for the upper 7 bits of a 10-bit
address (since the base address must be on 8-byte boundaries, the last three
bits are 0). To determine which jumpers to short, write the three hex char-
acters of the desired address, convert each to binary, ignore the two leading
zeros and the last three zeros, and then install jumpers to short the pin pairs
corresponding to the remaining zeros in the address.
As an example, suppose that you want to assign base I/O address 02E8h.
Converted to binary, this would be 0010 1110 1000. Bits A8 and A4 are ze-
ros, therefore, you would short pin pairs 3/4 and 11/12, leaving all the other
pairs open. Usually, the SSP will be used in addition to the XVME PC/AT
serial and parallel ports. Hence, Xycom recommends COM A be set to I/O
port 03E8, (see Table 2-4), COM B to 02E8 and the parallel port to 0278,
(see Table 2-7).
Table 2-7. Xycom Recommended I/O Address Selection
PC/AT
Port
SSP
Port I/O
Address Pins Shorted
1/2 3/4 5/6 7/8 9/10 11/13 13/14
COM3 COM A 3E8 short
COM4 COM B 2E8 short short
LPT2 Parallel 278 short short