1 files changed, 54 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/m68k/mvme167/timer/timerisr.S b/c/src/lib/libbsp/m68k/mvme167/timer/timerisr.S
new file mode 100644
index 0000000000..505e4b896a
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+++ b/c/src/lib/libbsp/m68k/mvme167/timer/timerisr.S
@@ -0,0 +1,54 @@
+/*  timer_isr()
+ *
+ *  This ISR is used to bump a count of interval "overflow" interrupts which
+ *  have occurred since the timer was started. The number of overflows is taken
+ *  into account in the Read_timer() routine.
+ *
+ *  Input parameters:  NONE
+ *
+ *  Output parameters:  NONE
+ *
+ *  COPYRIGHT (c) 1989-1998.
+ *  On-Line Applications Research Corporation (OAR).
+ *  Copyright assigned to U.S. Government, 1994.
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.OARcorp.com/rtems/license.html.
+ *
+ *  Modifications of respective RTEMS file: COPYRIGHT (c) 1994.
+ *  Copyright (c) 1998, National Research Council of Canada
+ *
+ *  $Id$
+ */
+
+#include "asm.h"
+
+BEGIN_CODE
+
+.set INTR_CLEAR_REG,    0xfff40074      | interrupt clear register
+.set T1_CNTRL_REG,      0xfff40060      | tick timer 1 control register
+.set CLEAR_INT,         0x01000000      | clear tick 1 interrupt
+.set CLEAR_OVF,         0x00000004      | clear tick 1 overflow counter
+
+        PUBLIC (Ttimer_val)
+        PUBLIC (timerisr)
+SYM (timerisr):
+        move.l  a0, -(a7)               | save a0
+        move.l  d0, -(a7)               | save d0
+        move.w  sr, -(a7)               | save ccr
+        movea.l #INTR_CLEAR_REG, a0     | a0 = addr of intr clr reg
+        ori.l   #CLEAR_INT, (a0)        | clear tick timer 1 intr
+        movea.l #T1_CNTRL_REG, a0       | a0 = addr of t1 cntrl reg
+        move.l  (a0), d0                | read overflow counter
+        lsr.l   #4, d0                  | put overflow in low order bits
+        andi.l  #0xF, d0                | keep only overflow
+        add.l   d0, SYM (Ttimer_val)    | increment timer value
+        ori.l   #CLEAR_OVF, (a0)        | clear overflow counter
+        move.w  (a7)+, sr               | restore ccr
+        move.l  (a7)+, d0               | restore d0
+        move.l  (a7)+, a0               | restore a0
+        rte
+
+END_CODE
+END