Specifications

Data Structures
1.7 Channel Request Block (CRB)
Figure 1–10 Interrupt Transfer Vector Block (VEC)
VEC$L_BUGCHECK* 0
VEC$L_RTINTD* (12 bytes) 4
VEC$L_INTD* 16
VEC$L_ISR 20
VEC$L_IDB* 24
VEC$L_INITIAL 28
VEC$W_MAPREGVEC$B_NUMREGVEC$B_DATAPATH 32
VEC$L_ADP* 36
VEC$L_UNITINIT* 40
VEC$L_START* 44
VEC$L_UNITDISC* 48
VEC$W_MAPALTVEC$W_NUMALT 52
*A read-only field
Table 1–9 Contents of Interrupt Transfer Vector Block (VEC)
Field Name Contents
VEC$L_BUGCHECK* Bugcheck data used to issue an ILLQBUSCFG bugcheck when the multilevel
interrupt dispatching code determines that the Q22–bus is illegally
configured.
VEC$L_RTINTD* Portion of interrupt transfer vector created at system initialization when a
MicroVAX system implements multilevel device interrupt dispatching. The
code stored in this 12-byte field implements a conditional lowering to device
IPL, as follows:
CMPZV #PSL$V_IPL, #PSL$S_IPL,-
4(SP), S^#DIPL
BGEQ BUGCHECK
SETIPL S^#DIPL
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