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/*  timer_isr()

 *

 *  This routine initializes the Z8536 timer on the SQSIO4 SQUALL

 *  board for the CVME961 board.  The timer is setup to provide a

 *  tick every 0x10000 / 2 milliseconds.  This is used to time

 *  executing code.

 *

 *  Input parameters:  NONE

 *

 *  Output parameters:  NONE

 *

 *  COPYRIGHT (c) 1989-1997.

 *  On-Line Applications Research Corporation (OAR).

 *  Copyright assigned to U.S. Government, 1994.

 *

 *  The license and distribution terms for this file may in

 *  the file LICENSE in this distribution or at

 *  http://www.OARcorp.com/rtems/license.html.

 *

 *  $Id: timerisr.S,v 1.2 2001-09-27 12:00:00 chris Exp $

 */

#include "asm.h"

.set PORT_A,     0xc00000a8                 # port A

.set PORT_B,     0xc00000a4                 # port B

.set PORT_C,     0xc00000a0                 # port C

.set CTL_PORT,   0xc00000ac                 # control port

.set T1CSR,      0x0a                       # T1 command/status reg

.set RELOAD,     0x24                       # clr IP & IUS,allow countdown

/*

 * Duplicating this symbol is stupid but eliminates

 * toolset variation problems.

 */

        PUBLIC(timerisr)

        PUBLIC(_timerisr)

SYM (timerisr):

SYM (_timerisr):

        #ldconst   1,r4

        #modpc     0,r4,r4               # enable tracing

        ld      _Ttimer_val,r6           # r6 = test timer

        ldconst T1CSR,r4                 # r4 = T1 control status reg

        stob    r4,CTL_PORT              # select T1CSR

        ldconst RELOAD,r5                # r5 = reset value

        stob    r5,CTL_PORT              # reset countdown

        addo    1,r6,r6

        st      r6,_Ttimer_val           # increment test timer

loop_til_cleared:

        /* clrbit 4,sf0,sf0 XXX JRS */

        /* bbs    4,sf0,loop_til_cleared XXX JRS */

leaf:   ret

        .leafproc _flush_reg, flush_reg.lf

        .globl    _flush_reg, flush_reg.lf

_flush_reg:

        lda     leaf,g14                 # g14 = exit address

flush_reg.lf:

        flushreg

        mov     g14,g0                   # g0 = exit address

        ldconst 0,g14                    # set g14 for non-leaf

        bx      (g0)