Technical data

Use of SED/SEE Fig. 3-8 illustrates the basic sequence of coordinated access using a
semaphore.
Before disabling or enabling a particular semaphore, the SED and SEE
operations scan the status of the semaphore. The condition codes CC 0
and CC 1 are affected as follows:
CC 1 CC 0 Evaluation Significance
0 0 JZ Semaphore was disabled by
another CPU and cannot be
disabled/enabled.
1 0 JN, JP Semaphore was disabled/
enabled.
START
Operation
successful?
Disable semaphore
Access to sema-
phore protected
global memory
Enable semaphore:
No
Yes
End
SED
SEE
Fig. 3-8 Coordination of access to the global memory
3
Semaphore Operations
CPU 928B Programming Guide
C79000-B8576-C898-01
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