Installation manual

Publication 1747-RM001G-EN-P - November 2008
SLC Status File B-43
S:24 Dynamic Config Index Register
This word indicates the element offset used in indexed
addressing.
When an STI, I/O Slot, or Fault Routine interrupts normal
execution of your program, the original value of this register
is restored when execution resumes.
••••
When a DII interrupts normal execution of your program, the
original value of this register is restored when execution
resumes.
•••
S:25
and
S:26
Status I/O Interrupt Pending
These two words are bit-mapped to the 30 I/O slots. Bits
S:25/1 through S:26/14 refer to slots 1 through 30. Bits
S:25/0 and S:26/15 are reserved.
The pending bit associated with an interrupting slot is set
when the corresponding I/O Slot Interrupt Enable bit is clear
at the time of an interrupt request. It is cleared when the
corresponding I/O Event Interrupt Enable bit is set, or when
an associated RPI instruction is executed.
The pending bit for an executing I/O interrupt subroutine
remains clear when the ISR is interrupted by an STI or fault
routine. Likewise, the pending bit remains clear if interrupt
service is requested at the time that a higher or equal
priority interrupt is executing (fault routine, STI, or other
ISR).
••••
The pending bit associated with an interrupting slot is set
when the corresponding I/O Slot Interrupt Enable bit is clear
at the time of an interrupt request. It is cleared when the
corresponding I/O Event Interrupt Enable bit is set, or when
an associated RPI instruction is executed. The pending bit is
always set when interrupt service is requested and the
processor is executing an interrupt of equal or higher
priority. Interrupt priority does not affect the setting of these
bits.
For example, while executing an STI subroutine, slot 6
requests an I/O Event Interrupt. The STI executes to
completion; however, slot 6 pending bit (S:25/6) becomes
set within execution of the STI. Examine the state of these
bits within your interrupt subroutines if your application
requires this information.
•••
Table B.4 Status File Functions (Continued)
Address Classification Description Fixed
5/01
5/02 5/03 5/04 5/05