Setting The Mode Register Bits - Brocade Communications Systems 1606 Administrator's Manual

3
Mode register bit settings
Each FICON director in a fabric must have a unique domain ID and a unique switch ID. The switch
ID used in the IOCP definitions can be any value between x'00' to x'FF'. The domain ID range for
directors is hex x'01' to x'EF' or decimal 1 to 239. When defining the switch IDs in the IOCP
definitions, ensure that you use values within the FICON director's range.
The switch ID has to be assigned by the user and must be unique within the scope of the
definitions (IOCP and HCD).
The domain ID is assigned by the manufacturer and can be customized to a different value. It must
be unique within the fabric.
Brocade recommends that the switch ID (in IOCP or HCD) be set to the same value as the domain
ID of the FICON director, which is defined to the FICON director at installation time. This simplifies
the configuration and reduces confusion by having a common designation across all definitions.
For more information on switch numbering, refer to the IBM publication FICON® Implementation
Guide (SG24-6497-00).
In the following sample IOCP configuration file, the UNIT value for FICON CUP definitions is 2032 for
any FICON director regardless of vendor or platform. All Brocade switches require UNIT=2032 for
the CUP definition. All Domain IDs are specified in hex values in the IOCP (and not in decimal
values).

Setting the mode register bits

Consider the following when changing mode register bits:
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*------------------------------------------------------------------
* Brocade Domain_ID=0x3c0000
*------------------------------------------------------------------
CNTLUNIT CUNUMBR=0D8,UNITADD=00,UNIT=2032,
PATH=(50,51),
LINK=(61FE,61FE)
IODEVICE ADDRESS=(0D8,1),CUNUMBR=0D8,UNIT=2032,STADET=Y,UNITADD=00
*---------------------------------------------------------------
CNTLUNIT CUNUMBR=0D9,UNITADD=00,UNIT=2032,
PATH=(8A,8B),
LINK=(22FE,22FE)
IODEVICE ADDRESS=(0D9,1),CUNUMBR=0D9,UNIT=2032,STADET=Y,UNITADD=00
*------------------------------------------------------------------
* Brocade Domain_ID=0x190000
*------------------------------------------------------------------
*
CNTLUNIT CUNUMBR=0DB,UNITADD=00,UNIT=2032,
PATH=(5A,5B),
LINK=(25FE,25FE)
IODEVICE ADDRESS=(0DB,1),CUNUMBR=0DB,UNIT=2032,STADET=Y,UNITADD=00
*
*------------------------------------------------------------------
The UAM bit can only be set by host programming.
All mode register bits except UAM are saved across power on/off cycles; the UAM bit is reset to
0 following a power-on.
Mode register bits can be changed when the switch is offline or online. If the ACP or HCP bits
are changed when the switch is online, they will take effect any time between the completion of
the current command and the end of the CCW command chain (or the next alternate manager
operation).
FICON Administrator's Guide
53-1001771-01