Specifications

Data Structures
1.2 Adapter Control Block (ADP)
Table 1–2 (Cont.) Contents of Adapter Control Block
Field Name Contents
ADP$V_DIRECT_VECTOR Direct-vector interrupts
ADP$V_AUTOPURGE_DP Autopurging datapath
ADP$V_BUFFERED_DP Buffered datapath supported
ADP$V_ODD_XFER_BDP Odd transfers supported on buffered data
path
ADP$V_ODD_XFER_DDP Odd transfers supported on direct data
path
ADP$V_EXTENDED_
MAPREG
Alternate map registers (registers 496 to
8191) supported
ADP$V_QBUS Q22–bus adapter
ADP$V_PSWITCH_COMMIT XMI adapters committed to primary
switch
ADP$V_CRAMIO Performs CRAM I/O
<15:11> Reserved to Digital
ADP$B_ADDR_BITS* Number of adapter address bits. This field contains the value 22 (for
Q22–bus systems) and 18 (for UNIBUS adapters).
ADP$L_PSWITCH_
CALLBACK*
Address of primary switch XMI callback
Field Name Contents
UNIBUS Adapter Extension
ADP$L_HOSTNODE* The offset to the bus-specific ADP extension.
ADP$L_MRQFL* Standard map register wait queue’s forward link and the first longword in
the UNIBUS adapter extension. IOC$ALOUBAMAP, IOC$REQMAPREG,
and IOC$RELMAPREG read and write these fields. When a driver fork
process requests a set of standard map registers and the set is not currently
available, IOC$REQMAPREG saves driver fork context in the device’s UCB
fork block, inserts the fork block address in the standard-map-register wait
queue, and suspends the driver fork process.
When another driver calls IOC$RELMAPREG to release a set of standard
map registers, the routine dequeues a UCB fork block address from the
standard-map-register wait queue, allocates the requested set of map
registers to the driver, and reactivates that driver fork process.
ADP$L_MRQBL* Standard-map-register wait queue’s backward link. IOC$ALOUBAMAP,
IOC$REQMAPREG, and IOC$RELMAPREG read and write this field.
ADP$L_INTD_UBA* Interrupt transfer vector. The system adapter initialization routine places
executable code in this field to allow certain Digital-supplied adapters or
controllers to dispatch to adapter-specific interrupt and error handling
routines.
ADP$L_UBASCB* Series of four longwords that contain SCB entry values, one for each bus
request (BR) level or interrupt vector. The UNIBUS adapter power failure
recovery procedure uses these values.
ADP$L_UBASPTE* System page-table entry (PTE) values for base of UNIBUS adapter register
space and base of UNIBUS I/O register space. These values contained in
this quadword field are used during UNIBUS adapter power failure recovery.
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