Changeset 4dd1aa5 in rtems

Timestamp:

01/22/01 14:11:09 (22 years ago)

Author:

Joel Sherrill <joel.sherrill@…>

Branches:

4.10, 4.11, 4.8, 4.9, 5, master

Children:

9f87484

Parents:

d6b1d73

Message:

2001-01-22 Radzislaw Galler <rgaller@…>

• clock/ckinit.c (Install_clock): Modified MTU timer 0 initialization to generate an interrupt exactly every 1us

Location:

c/src/lib/libcpu/sh/sh7045

Files:

• ChangeLog (modified) (1 diff)
• clock/ckinit.c (modified) (6 diffs)

c/src/lib/libcpu/sh/sh7045/ChangeLog

@@ +1 @@
+2001-01-22  Radzislaw Galler  <rgaller@et.put.poznan.pl>
+
+        * clock/ckinit.c (Install_clock): Modified MTU timer 0 initialization
+        to generate an interrupt exactly every 1us
+
 2001-01-05      Joel Sherrill <joel@OARcorp.com>
 

c/src/lib/libcpu/sh/sh7045/clock/ckinit.c

@@ -45 +45 @@
 #include <rtems/score/iosh7045.h>
 
-#define _MTU_COUNTER0_MICROSECOND (Clock_MHZ/4)
+#define _MTU_COUNTER0_MICROSECOND (Clock_MHZ/16)
 
 #ifndef CLOCKPRIO
@@ -54 +54 @@
 #define MTU0_SYNCMASK   0xfe
 #define MTU0_MODEMASK   0xc0
-#define MTU0_TCRMASK    0x01 /* bit 7 also used, vs 703x */
+#define MTU0_TCRMASK    0x22 /* bit 7 also used, vs 703x */
 #define MTU0_STAT_MASK  0xc0
 #define MTU0_IRQMASK    0xfe
@@ -151 +151 @@
 {
   unsigned8 temp8 = 0;
+  unsigned32 factor = 1000000;
+  
   
   /*
@@ -159 +161 @@
   Clock_isrs_const = rtems_configuration_get_microseconds_per_tick() / 10000;
   Clock_isrs = Clock_isrs_const;
-
-  Clock_MHZ = rtems_cpu_configuration_get_clicks_per_second() / 1000000 ;
+  
+  factor /= rtems_configuration_get_microseconds_per_tick(); /* minimalization of integer division error */
+  Clock_MHZ = rtems_cpu_configuration_get_clicks_per_second() / factor ;
 
   rtems_interrupt_catch( Clock_isr, CLOCK_VECTOR, &Old_ticker );
@@ -183 +186 @@
   write8( temp8, MTU_TMDR0);
 
-  /* TCNT is cleared by GRA ; internal clock /4 */
+  /* TCNT is cleared by GRA ; internal clock /16 */
   write8( MTU0_TCRMASK , MTU_TCR0);
 
@@ -202 +205 @@
 
   /* set counter limits */
-  write16( _MTU_COUNTER0_MICROSECOND * 
-    rtems_configuration_get_microseconds_per_tick(), MTU_GR0A);
+  write16( _MTU_COUNTER0_MICROSECOND, MTU_GR0A);
    
   /* start counter */