SYSTEM 0BJECrS srRUCTURES
Selected Index and Selected State Fields -
The selected index and selected state fields are filled in by the processor fram information found in the process carrier data segment at process selection time, i. e when a "select process" IPC is received. The selected index is a process selection index used to conmunicate to Attached Processor software which process from the process selection list has just been bound to the processor. The selected index is obtained from the double byte quantity located at a displacement of eight double bytes into the process carrier data segment. The selected state is uninterpreted by processors and is obtained from the double byte quantity located at a displacement of nine double bytes into the process carrier data segment.
Processor Fault Information Area
The organization of the processor fault information area is described in Appendix C.
Local and Global Communication Segments
Both local and global oonununication segments used by IPs have the same format and interpretation as the corresponding objects employed by GDPs.
IPC Message Field
The IPC message field contains one of the following function request encodings. Message codes 0 through 7 represent IPC messages which are coll'lIDn between GDPs and IPs. Message codes 15, 16, and 17 are messages specific to Interface Processors. Message codes 8 through 14 are defined for GDPs rut are unused by IPs.
o - Select Process - Causes the processor to examine its carr ier to determine if a process was received. If a process was received, the process is selected, the dispatching flag is set, and the selected state and selected index fields are copied from the process carrier data segment to the control
1 - Start Processor
2 - Stop Processor
3 - Set broadcast acceptance mode
