Use Of Ccu (Menu 2) Functions With Diagnostics - IBM 3745 Series Service Functions

Use of CCU (Menu 2) Functions with Diagnostics
When running CCU diagnostics or 'RUN ALL', you can use the CCU (menu 2)
functions, but unpredictable results may occur.
When running TSS, HPTSS, TRSS, CA diagnostics, the CCU is not used as a
processor.
Only the last 10K of CCU storage are used as 'scanner mailbox' for data
exchange between the OCM in the MOSS and the CP-and-IFTs in the TSS.
There is no need to use the CCU functions when running TSS diagnostics,
except if you wish to display the 'scanner mailbox'. Setting an address
compare, for example, has no meaning.
Restrictions of CCU Functions Use with Diagnostics
The following CCU functions may lead to unpredictable results:
• CID (channel interface display)
• .RCL (reset CCU/LSSO)
• IL3 (CCU level 3 interrupt)
• RIO (reset IOC).
To use address compare and branch trace, the CCU must first be initialized.
The setting of these two functions remains active as long as the CCU is not re-
initialized (indicated by 'RESET' on the MSA).
Note: For branch trace, local storage X7D' must contain X' 1 0000'< (address of
the branch trace buffer), and local storage X'7C' must contain X'6000' (length of
the branch trace buffer). Check the local storages for these values, and set
them to the correct values when required.
Chapter 3. Diagnostics
3-9