Specifications

320 Appendix B
Status Reporting System
General Status Register Model
Condition register and transition filter
When the status register has a transition filter, there is a lower register called a condition
register under the event register. The transition filter is between the event register and the
condition register.
The transition filter enables you to select a positive and/or negative transition of the
condition register bit in order to set a bit in the corresponding event register. For example,
using the negative transition filter to set bit 3 to “1” causes bit 3 of the event register to be
set to “1” when bit 3 of the condition register makes a negative transition, that is, changes
from 1 to 0,
Figure B-2 Transition filter and condition register
The 4287A's condition register and transition filter work only with the operation status
register.