Table 9–1 : Unprivileged OpenVMS Alpha PALcode Instruction Summary (Continued)

Mnemonic

Operation and Description

REMQUEL

Remove from longword queue

 

The queue entry addressed by R16 for REMQUEL or the entry addressed by

 

the longword addressed by R16 for REMQUEL/D is removed from the long-

 

word absolute queue, and the address of the removed entry is returned in R1.

 

The removal is a noninterruptible operation.

REMQUEQ

Remove from quadword queue

 

The queue entry addressed by R16 for REMQUEQ or the entry addressed by

 

the quadword addressed by R16 for REMQUEL/D is removed from the quad-

 

word absolute queue, and the address of the removed entry removed is

 

returned in R1. The removal is a noninterruptible operation.

RSCC

Read system cycle counter

 

Register R0 is written with the value of the system cycle counter. This counter

 

is an unsigned 64-bit integer that increments at the same rate as the process

 

cycle counter. The system cycle counter is suitable for timing a general range

 

of intervals to within 10% error and may be used for detailed performance

 

characterization.

SWASTEN

Swap AST enable

 

SWASTEN swaps the AST enable bit for the current mode. The new state for

 

the enable bit is supplied in register R16<0> and previous state of the enable

 

bit is returned, zero-extended, in R0. A check is made to determine if an AST

 

is pending. If the enabling conditions are present for an AST at the completion

 

of this instruction, the AST occurs before the next instruction.

WRITE_UNQ

Write unique context

 

WRITE_UNQ writes the hardware process (thread) unique context value

 

passed in R16 to internal storage or to the hardware privileged context block.

WR_PS_SW

Write processor status software field

 

WR_PS_SW writes the Processor Status software field (PS<SW>) with the

 

low-order three bits of R16<2:0>.

 

 

9–7

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Compaq ECQD2KCTE manual Remquel, Remqueq, Rscc, Swasten, Writeunq, Wrpssw