Setup TMR0 to correctly generate ticks upon configTICK_RATE_HZ value

5 files changed, 23 insertions, 20 deletions

diff --git a/Demo/PIC18_SDCC/FreeRTOSConfig.h b/Demo/PIC18_SDCC/FreeRTOSConfig.h
index ce6dec9c..be910a44 100644
--- a/Demo/PIC18_SDCC/FreeRTOSConfig.h
+++ b/Demo/PIC18_SDCC/FreeRTOSConfig.h
@@ -1,7 +1,7 @@
 /**
-* ###################################################################################
+* #######################################################################################
 * Gaye Abdoulaye, <walsimou@walsimou.com>
-* Copyright (C) 2009 Gaye Abdoulaye, <walsimou@walsimou.com>.  All rights reserved.
+* Copyright(C) 2009 GAYE Abdoulaye Walsimou, <walsimou@walsimou.com>. All rights reserved.
 *
 * This program is free software; you can distribute it and/or modify it
 * under the terms of the GNU General Public License
@@ -15,14 +15,14 @@
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
-* ###################################################################################
+* #######################################################################################
 *
 * \file         FreeRTOSConfig.h
 * \brief	FreeRTOSConfig.h for SDCC PIC18 (pic16 arch in sddc world) port.
 * \brief	It is based on other PIC18 port.
-* \author       Gaye Abdoulaye, <walsimou@walsimou.com>
+* \author       GAYE Abdoulaye Walsimou, <walsimou@walsimou.com>
 * \date         february 2009
-* ###################################################################################
+* #######################################################################################
 */
 
 #ifndef FREERTOS_CONFIG_H
@@ -31,7 +31,7 @@
 #define configUSE_PREEMPTION			1
 #define configUSE_IDLE_HOOK			0
 #define configUSE_TICK_HOOK			0
-#define configTICK_RATE_HZ			((portTickType)9766)
+#define configTICK_RATE_HZ			((portTickType)1000)
 #define configCPU_CLOCK_HZ			((unsigned portLONG)20000000)
 #define configMAX_PRIORITIES			((unsigned portBASE_TYPE)5)
 /*Since in main.c we define a hardwre stack to be 64bytes in size,
diff --git a/Demo/PIC18_SDCC/Makefile b/Demo/PIC18_SDCC/Makefile
index 1b0ea5e2..488c64c3 100644
--- a/Demo/PIC18_SDCC/Makefile
+++ b/Demo/PIC18_SDCC/Makefile
@@ -1,6 +1,6 @@
-###################################################################################
-# Gaye Abdoulaye, <walsimou@walsimou.com>
-# Copyright (C) 2009 Gaye Abdoulaye, <walsimou@walsimou.com>  All rights reserved.
+#########################################################################################
+# GAYE Abdoulaye Walsimou, <walsimou@walsimou.com>
+# Copyright(C) 2009 GAYE Abdoulaye Walsimou, <walsimou@walsimou.com>  All rights reserved.
 #
 # This program is free software; you can distribute it and/or modify it
 # under the terms of the GNU General Public License
@@ -18,7 +18,7 @@
 #
 # \file         Makefile
 # \brief	Makefile of root project
-# \author       Gaye Abdoulaye, <walsimou@walsimou.com>
+# \author       GAYE Abdoulaye Walsimou, <walsimou@walsimou.com>
 # \date         February 2009
 ###################################################################################
 
diff --git a/Demo/PIC18_SDCC/main.c b/Demo/PIC18_SDCC/main.c
index 6d12f4cb..729101c9 100644
--- a/Demo/PIC18_SDCC/main.c
+++ b/Demo/PIC18_SDCC/main.c
@@ -1,7 +1,7 @@
 /**
 * #######################################################################################
 * GAYE Abdoulaye Walsimou, <walsimou@walsimou.com>
-* Copyright(C) 2009 Gaye Abdoulaye Walsimou, <walsimou@walsimou.com>. All rights reserved.
+* Copyright(C) 2009 GAYE Abdoulaye Walsimou, <walsimou@walsimou.com>. All rights reserved.
 *
 * This program is free software; you can distribute it and/or modify it
 * under the terms of the GNU General Public License
diff --git a/Source/portable/SDCC/PIC18/port.c b/Source/portable/SDCC/PIC18/port.c
index 86c52bad..7bdf0fef 100644
--- a/Source/portable/SDCC/PIC18/port.c
+++ b/Source/portable/SDCC/PIC18/port.c
@@ -83,9 +83,9 @@ static void prvSetupTimerInterrupt(void);
  * When MR0ReloadValue=0 (65536 increments) configTICK_RATE_HZ=76Hz (with respect to values in FreeRTOSConfig.h)
  * When MR0ReloadValue=65535 (1 increment) configTICK_RATE_HZ=5MHz (with respect to values in FreeRTOSConfig.h)
  * This implies the bellow linear relation between configTICK_RATE_HZ and TMR0ReloadValue
- * , if we accept that 1 is negligible with respect to 65535.
+ * TMR0ReloadValue=65536 - configCPU_CLOCK_HZ/(portTIMER_FOSC_SCALE*configTICK_RATE_HZ)
  */
-portSHORT TMR0ReloadValue=(portSHORT)(65536.0 -(float)(portTIMER_FOSC_SCALE*65536.0*configTICK_RATE_HZ/configCPU_CLOCK_HZ)+65537.0);
+const unsigned portSHORT TMR0ReloadValue=(65536 - configCPU_CLOCK_HZ/(configTICK_RATE_HZ*portTIMER_FOSC_SCALE));
 
 
 /*
@@ -202,7 +202,7 @@ portBASE_TYPE xPortStartScheduler(void)
 
 	/* Restore the context of the first task to run. */
 	portRESTORE_CONTEXT();
-
	/* Should not get here.  Use the function name to stop compiler warnings. */
+	/* Should not get here.  Use the function name to stop compiler warnings. */
 	( void ) prvLowInterrupt;
 
 	return pdTRUE;
@@ -254,7 +254,11 @@ void vPortYield(void) __naked
                 /* Interrupts must have been enabled for the ISR to fire, so we have to
                 save the context with interrupts enabled. */
                 portSAVE_CONTEXT(portGLOBAL_INTERRUPT_FLAG);
+
                 INTCONbits.TMR0IF=0;
+                /*set TMR0L and TMR0H vlaue*/
+                TMR0H=(unsigned portCHAR)((TMR0ReloadValue&(unsigned portSHORT)0xff00)>>8);
+                TMR0L=(unsigned portCHAR)(TMR0ReloadValue&(unsigned portSHORT)0x00ff);
 
                 /* Maintain the tick count. */
                 vTaskIncrementTick();
@@ -283,15 +287,13 @@ static void prvSetupTimerInterrupt(void)
 	INTCONbits.TMR0IF=0;    /*Timer0 interrupt flag cleared*/
 	INTCON2bits.T0IP=0;     /*TimerO has low priority interrupt*/
 
-        /**/
-        TMR0H=0x00;             /*Initialize timer0 high byte register*/
-        TMR0L=0x00;             /*Initialize timer0 low byte register*/
-
+        /*set TMR0L and TMR0H vlaue*/
+        TMR0H=(unsigned portCHAR)((TMR0ReloadValue&(unsigned portSHORT)0xff00)>>8);
+        TMR0L=(unsigned portCHAR)(TMR0ReloadValue&(unsigned portSHORT)0x00ff);
 	RCONbits.IPEN=1;        /* Interrupt priority feature enabled. FIXME: this is
                                  * something like hardware interrupt controller configu-
                                  * ration, so needs to be done somewhere else I think
                                  */
-
         T0CONbits.TMR0ON=1;     /*Now enable timer0*/
 }
 
diff --git a/Source/portable/SDCC/PIC18/portmacro.h b/Source/portable/SDCC/PIC18/portmacro.h
index 48e8ad2d..013eb01a 100644
--- a/Source/portable/SDCC/PIC18/portmacro.h
+++ b/Source/portable/SDCC/PIC18/portmacro.h
@@ -1,7 +1,7 @@
 /**
 * #######################################################################################
 * GAYE Abdoulaye Walsimou, <walsimou@walsimou.com>
-* Copyright (C) 2009 Gaye Abdoulaye, <walsimou@walsimou.com>.  All rights reserved.
+* Copyright(C) 2009 GAYE Abdoulaye walsimou, <walsimou@walsimou.com>. All rights reserved.
 *
 * This program is free software; you can distribute it and/or modify it
 * under the terms of the GNU General Public License
@@ -29,6 +29,7 @@
 #define PORTMACRO_H
 
 #include <pic18fregs.h>
+#include <math.h>
 
 /*-----------------------------------------------------------
  * Port specific definitions.