3088 Address pairing by MPIF

The 3088 MCCU supports channel communication between 2, 4, or 8 processors (depending on 3088 model). A processor physically attaches to one of the 3088’s channel adapters. The physical channel adapter is assigned a base control unit address. Starting with this address, a range of 32 or 64 addresses is provided. The base address in a 32-address configuration may be xx00, xx20, xx40, xx60, xx80, xxA0, xxC0 or xxE0 (xx = unrestricted value). The base address in a 64-address configuration may be xx00, xx40, xx80 or xxC0.

MPIF supports the definition of 3088 address ranges of size 2 to 64 (even numbers only). The address range defined to MPIF does not have to begin at the base address.

MPIF will pair individual addresses; logical paths will use one address for read operations and the other for write operations. The following table lists the address pairs that will be assigned. Each address is described as a displacement from the base address. Add the displacements in the table to the base control unit address to compute the pairs for a range of addresses. For example, the address pairs for a 32-address Model 1 communication unit with a base address of 0EA0 would be 0EA0-0EA1, 0EA2-0EA3, 0EA4-0EA5, 0EA6-0EA7… If only addresses 0EA8-0EB7 were defined to MPIF, the address pairs would be 0EA8-0EA9, 0EAA-0EAB, 0EB0-0EB1, 0EB2-0EB3, 0EB4-0EB5, 0EB6-0EB7.

Model 1A (two-way) Model 1 (four-way) Model 2 (eight-way)
00 - 01 00 - 01 00 - 01
02 - 03 02 - 03 02 - 03
04 - 05 04 - 05 04 - 05
06 - 07 06 - 07 06 - 07
08 - 09 08 - 09 08 - 09
0A - 0B 0A - 0B 0A - 0B
0C - 1C 0C - 1C 0C - 0D
0D - 1D 0D - 1D 0E - 0F
0E - 1E 0E - 1E 10 - 11
10 - 11 10 - 11 12 - 13
12 - 13 12 - 13 14 - 15
14 - 15 14 - 15 16 - 17
16 - 17 16 - 17 18 - 19
18 - 19 18 - 19 1A - 1B
1A - 1B 1A - 1B 20 - 21
20 - 21 20 - 21 22 - 23
22 - 23 22 - 23 24 - 25
24 - 25 24 - 25 26 - 27
26 - 27 26 - 27 28 - 29
28 - 29 28 - 29 2A - 2B
2A - 2B 2A - 2B 2C - 2D
2C - 3C 2C - 3C 2E - 2F
2D - 3D 2D - 3D 30 - 31
2E - 3E 2E - 3E 32 - 33
30 - 31 30 - 31 34 - 35
32 - 33 32 - 33 36 - 37
34 - 35 34 - 35 38 - 39
36 - 37 36 - 37 3A - 3B
38 - 39 38 - 39  
3A - 3B 3A - 3B