IBM System/370 145 Reference Summary page 71

II
UCWPOOL
Number of
Groups of
16
2
3
4
5
6
UCW+ 1 =
9000
9080
9100
92CO
=Even
9088 !)090 9098
90A0
~
90A8 9080
9088
90CO
90C8 9000 9008
901$0
90E8
UCW Pool
----==::::----
- -
-
31r::
32~
Maximum UCW Pool Boundary
Maximum
UCW+l
=
9AOO
UCW ASSIGNMENT REGISTERS
Control
Storage
FFD4
FFD8
r-
Control Reg 0 Bit 0 =DCC Mode
0123---- Start UCW Poll
End UCW Poll +1 Next/Current Group
Example~l-:--- 2
_ _.__C _ _ _
0
_+-_9_
9
___
~---:---~-t
UCW FORMAT
UCW Format
Key Next CCW
Channel
0 1 2 3 4 5 6 7 Status
Subchannel Active
Interruption Pending
- - - • Command Chaining
----•Command Retry
9078
- Shared UCWs
90f0
90F8
- Un;hared UCWs
9288
-
-
Address
Count
4.6