.TITLE   DELAY
;----------------------------------------------------------------------;
;       SUBROUTINE:   DELAY                                            ;
;----------------------------------------------------------------------;
;       LANGUAGE:     VAX-11 MACRO ASSEMBLY LANGUAGE                   ;
;       SYSTEM:       VAX-11/780                                       ;
;                     MOSTEK CORPORATION                               ;
;                     COMPUTER AIDS TO DESIGN DIVISION                 ;
;                     1215 WEST CROSBY ROAD                            ;
;                     CARROLLTON, TEXAS  75006                         ;
;                     (214)  323-8813                                  ;
;----------------------------------------------------------------------;
;       PROGRAMMER:   KEVIN KLUGHART                                   ;
;----------------------------------------------------------------------;
;       DATE:         05-21-81 @ 13:00 CDST                            ;
;----------------------------------------------------------------------;
;       PURPOSE:      THIS SUBROUTINE DELAYS THE EXECUTION OF A        ;
;                     PROCESS A SPECIFIED AMOUNT OF TIME.  THIS        ;
;                     EXECUTION DELAY IS COMPUTED AS FOLLOWS:          ;
;                                                                      ;
;                                                                      ;
;                     1.  IF (TIME_DELAY <= 0) THEN THE PASSED         ;
;                         PARAMETER REPRESENTS THE NUMBER OF 100-      ;
;                         NANOSECOND UNITS TO ELAPSE BEFORE            ;
;                         PROGRAM EXECUTION IS RESUMED.                ;
;                                                                      ;
;                     2.  IF (TIME_DELAY > 0) THEN THE PASSED          ;
;                         PARAMETER REPRESENTS THE NUMBER OF           ;
;                         MILLISECOND UNITS TO ELAPSE BEFORE           ;
;                         PROGRAM EXECUTION IS RESUMED.                ;
;----------------------------------------------------------------------;
;       NOTES:        THIS SUBROUTINE ASSUMES THAT THE SYSTEM CLOCK    ;
;                     HAS UNIT INCREMENTS OF 100-NANOSECONDS, WHICH    ;
;                     IS CONSISTENT WITH THE VAX-11/780 SYSTEM         ;
;                     TIME QUADWORD FORMAT STANDARD.                   ;
;----------------------------------------------------------------------;
;       REFERENCES:   VAX-11/780 SYSTEM SERVICES REFERENCE             ;
;----------------------------------------------------------------------;
        .PAGE
        .SBTTL  DATA:     SYSTEM DELTA-TIME QUADWORDS
;----------------------------------------------------------------------;
;                                                                      ;
;       DATA AREA                                                      ;
;                                                                      ;
;----------------------------------------------------------------------;
;       DEFINE THE SYSTEM DELTA-TIME QUADWORD DATA AREAS               ;
;----------------------------------------------------------------------;
        .PSECT  DELAY$DATA,QUAD

        .ALIGN  QUAD
DELTIM: .QUAD   0               ; NORMAL PROCESS LEVEL DELTA-TIME QUADWORD 
DELAST: .QUAD   0               ; AST LEVEL DELTA-TIME QUADWORD
        .PAGE
        .SBTTL  CODE:     DELAY PROCESS EXECUTION 
;----------------------------------------------------------------------;
;                                                                      ;
;       DELAY:     DELAY PROCESS EXECUTION THE SPECIFIED TIME INTERVAL ;
;                                                                      ;
;----------------------------------------------------------------------;
;       THIS ENTRYPOINT IS INTENDED FOR EXECUTION IN NORMAL PROCESS    ;
;       MODE.  THIS ENTRYPOINT IS NOT REENTRANT.                       ;
;----------------------------------------------------------------------;
        .PSECT  DELAY$CODE
        .ENTRY  DELAY,^M<R2,R3,R4,R5,R6,R7,R8,R9,R10,R11>


        MOVL    @4(AP),R0               ; GET FIRST PARAMETER (TIME_DELAY)
        BGEQ    MS_DLY                  ; IF >= 0, USE MILLISECOND DELAY
        MOVL    R0,DELTIM               ; CONVERT TO SYSTEM TIME (QUAD)
        MOVL    #-1,DELTIM+4            ; INITIALIZE DELTA-TIME LONGWORD
        JMP     HIBNML                  ; DELAY SET:  NOW EXECUTE WAIT

MS_DLY: EMUL    R0,#-10000,#0,DELTIM    ; CONVERT DELAY TO MILLISECONDS

HIBNML: $SCHDWK_S ,,DELTIM,             ; SCHEDULE PROCESS WAKE-UP (DELAY)
        $HIBER_S                        ; HIBERNATE UNTIL AWOKEN
        BRB     EXIT
        .PAGE
        .SBTTL  CODE:     AST LEVEL DELAY PROCESS EXECUTION
;----------------------------------------------------------------------;
;                                                                      ;
;       DELAY_AST:     DELAY AST EXECUTION THE SPECIFIED TIME INTERVAL ;
;                                                                      ;
;----------------------------------------------------------------------;
;       THIS ENTRYPOINT IS INTENDED FOR EXECUTION AT AST LEVEL.        ;
;       THIS ENTRYPOINT IS NOT REENTRANT.                              ;
;----------------------------------------------------------------------;
        .ENTRY  DELAY_AST,^M<R2,R3,R4,R5,R6,R7,R8,R9,R10,R11>


        MOVL    @4(AP),R0               ; GET FIRST PARAMETER (TIME_DELAY)
        BGEQ    MS_AST                  ; IF >= 0, USE MILLISECOND DELAY
        MOVL    R0,DELAST               ; CONVERT TO SYSTEM TIME (QUAD)
        MOVL    #-1,DELAST+4            ; INITIALIZE DELTA-TIME LONGWORD
        JMP     HIBAST                  ; DELAY SET:  NOW EXECUTE WAIT

MS_AST: EMUL    R0,#-10000,#0,DELAST    ; CONVERT DELAY TO MILLISECONDS

HIBAST: $SCHDWK_S ,,DELAST,             ; SCHEDULE PROCESS WAKE-UP (DELAY)
        $HIBER_S                        ; HIBERNATE UNTIL AWOKEN
;----------------------------------------------------------------------;
;       END OF SUBROUTINE DELAY                                        ;
;----------------------------------------------------------------------;
EXIT:   RET
        .END