cpu-id

    Numeric value indicating the identity of the CPU for which
    context information is to be displayed. This parameter changes
    the SDA current CPU (the default) to the CPU specified with cpu-
    id. If you specify the cpu-id of a processor that was not active
    at the time of the system failure, SDA displays the following
    message:

    %SDA-E-CPUNOTVLD, CPU not booted or CPU number out of range

    If you use the cpu-id parameter, the SHOW MACHINE_CHECK command
    performs an implicit SET CPU command, making the CPU indicated by
    cpu-id the current CPU for subsequent SDA commands.