OS-9 Device Descriptor and Configuration Module Reference

Low-Level System Configuration Module (cnfgdata)cons_priorityEditMod Labels2-configuration data1-console port data structure3-interrupt priorityCOMM_PRIORITY1DescriptionThis is the software (polling) priority for the console device on the IRQpolling table.Port Generic Default Value0 (zero)Port Specific Override ValueRefer to ROM/CNFGDATA/config.des (Figure 1-3).Available ValuesThe interrupt priority value range is 0-65534 (65535 is reserved). Anon-zero priority determines the position of the device within the vector.Lower values are polled first.Some considerations to keep in mind when selecting an interruptpriority:• A priority of 0 indicates the device desires exclusive use of thevector.• If the priority is 1, it is polled first and no other device can have apriority of 1 on the vector. For all other priority values, more than onedevice may share the same priority on a vector. In this case, first-in,first-out (FIFO) scheduling determines the order of precedence inthe polling table for the devices.OS-9 Device Descriptor and Configuration Module Reference 49