In CICS PA, the term clock is distinguished
from the term time stamp:
- Clock
- A 32-bit value, expressed in units of 16 microseconds, accumulated
during one or more measurement periods. The 32-bit value is followed
by 8 reserved bits, which are in turn followed by a 24-bit value indicating
the number of measurements periods.
Neither the 32-bit timer component
of the clock nor its 24-bit period count are protected against wraparound.
The timer capacity is about 18 hours, and the period count runs to
modulo-16 777 216.
The eight reserved bits have the following
significance:
- Bits 0, 1, 2, and 3
- Used for online control of the clock when it is running, and
should always be zero on output.
- Bits 4 and 7
- Not used.
- Bits 5 and 6
- Used to indicate, when set to 1, that the clock has suffered
at least one out-of-phase start (bit 5) or stop (bit 6).
- Time Stamp
- An 8-byte copy of the output of a STCK instruction.