Specifications

Data Structures
1.15 SCSI Class Driver Request Packet (SCDRP)
Table 1–17 (Cont.) Contents of SCSI Class Driver Request Packet
Field Name Contents
SCDRP$L_SAVER3* Reserved to Digital.
SCDRP$L_SAVER6* Reserved to Digital.
SCDRP$L_SAVER7* Reserved to Digital.
SCDRP$L_SAVER3CL* Reserved to Digital.
SCDRP$L_SAVEPCCL* Reserved to Digital.
SCDRP$L_ABORTPCCL* Reserved to Digital.
SCDRP$L_PO_STK_PTR* Stack pointer of the port driver’s return address stack.
SCDRP$L_PO_STK* Port driver’s return address stack. This stack is 24 bytes long.
SCDRP$L_TAG* Reserved to Digital.
SCDRP$W_QUEUE_TAG SCSI-2 queue tag for this I/O allocated by the port driver. For more complex
ports where the tag allocation is done by adapter firmware, this field is
undefined.
SCDRP$W_QUEUE_CHAR SCSI-2 queuing characteristic specified for this I/O. This field is filled in
by the SPI$QUEUE_COMMAND as the class driver specifies one of the
following values:
0 SCDRP$K_UNORDERED
1 SCDRP$K_HEAD
2 SCDRP$K_ORDERED
3 SCDRP$K_NOT_QUEUED
4 SCDRP$K_ERROR_RECOVERY
SCDRP$L_CLASS_STACK_
PTR
Class driver return address stack pointer for SCSI-2 devices only.
SCDRP$L_CLASS_STACK Class driver return address stack for SCSI-2 devices only (replaces UCB$L_
STACK).
SCDRP$L_PQFL Port (incoming and in-device) queue forward link used by INSQUE and
REMQUE.
SCDRP$L_PQBL Port (incoming and in-device) queue backward link.
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