gtpm3m0yMulti-Processor Interconnect Facility Reference


Appendix A. Example of a MPIF Loosely Coupled Complex Initialization

Detailed below is a sample MPIF loosely coupled complex and the commands required to initialize the complex. It is assumed that the system has been generated with the MPIF function included and the appropriate address ranges have been included for the channel-to-channel (CTC) communication links.

Figure 7. Sample MPIF Loosely Coupled Complex. CTC represents channel-to-channel support.


Notes on the Sample Configuration:

  1. There are three paths between each processor in the loosely coupled complex with subchannel addresses and device names as follows:
    Channel # Address Range Generated Actual Addresses Available Device Name
    1 0320-033F 0320-0323 $CTOCA1
    2 0340-035F 0340-0341 $CTOCA2
    3 0320-033F 0320-0323 $CTOCA1
    4 0340-035F 0340-0341 $CTOCA2

  2. The number of subchannels per channel for a 3088 device can be any even number from 2 through 64, although all subchannel addresses may not be available. An ESCON CTC can have between 2 and 128 physical links. Thirty-two subchannel addresses are shown above for each path.

    MPIF requires a pair of addresses to define a logical path, one address for reading and one for writing. MPIF will do the pairing of addresses automatically.

  3. There are four addresses in use on channels 1 and 3 because there are two logical paths across these channels.

  4. The device names and address ranges are the same on both processors, which gives the loosely coupled complex symmetry.