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deepakomanna
Joined: 06 Mar 2007
Posts: 92
Location: Pune,India
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| getting garbage data by using "byte const " |
 Posted: Fri Apr 06, 2007 1:59 am |
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Dear Sir,
here i am using 16f684, MPLAB 7.5 Ver. & CCS PCM C Compiler, Version 3.249, 34534.
in this programe i want to store arrays data in ROM.
so i declare arrays like this,
BYTE CONST RPM_COUNT[14] = {7500,6000,5000,4839,3571,3333,3000,2727,2308,2143,2000,1875,1765,1667};
BYTE CONST SLOPE[13] = {89,1,-106,4,24,3,3,3,-16,-95,11,-102,18};
BYTE CONST DELAY_COUNT[13] = {542,17,14,81,60,37,33,30,21,25,79,83,120};
These are called in function.But after compling & doing single steping i found that the value
stored in these arrays is different.
So plz tell me what is wrong with my code,Plz Refer following code.
| Code: |
#include <16F684.h>
#fuses INTRC_IO,NOWDT,PUT,NOMCLR,PROTECT,NOCPD,NOBROWNOUT,NOPROTECT,NOIESO,NOFCMEN
//Internal RC Osc, no CLKOUT,No Watch Dog Timer,Power Up Time ON,Internal MCLR,Code Protect ON,No EE protection,Brownout detect OFF,
#use delay(clock=8000000)
void init_CPU();
unsigned int16 CALCULATION_FUNCTION(unsigned int16);
BYTE const RPM_COUNT[14] = {7500,6000,5000,4839,3571,3333,3000,2727,2308,2143,2000,1875,1765,1667};
BYTE const SLOPE[13] = {89,1,-106,4,24,3,3,3,-16,-95,11,-102,18};
BYTE const DELAY_COUNT[13] = {542,17,14,81,60,37,33,30,21,25,79,83,120};
unsigned int16 DLY_CNT,RPM_CNT;
void main()
{
int8 j =0;
init_CPU();
while(j != 12)
{
RPM_CNT = 6500;
DLY_CNT = CALCULATION_FUNCTION(RPM_CNT);
RPM_CNT += 500;
j++;
}
}
unsigned int16 CALCULATION_FUNCTION(unsigned int16 TIMER_COUNT)
{
int8 i;
signed int32 DLY_CNT1;
unsigned int16 DLY = 0;
for(i = 0; i <= 12; i++)
{
if((TIMER_COUNT <= RPM_COUNT[i]) && (TIMER_COUNT >= RPM_COUNT[i + 1]))
{
DLY_CNT1 = RPM_COUNT[i] - TIMER_COUNT;
DLY_CNT1 = (signed int32)(SLOPE[i] * DLY_CNT1); // int32
DLY_CNT1 = (signed int32)DLY_CNT1 >> 8;
DLY = (unsigned int16) (DELAY_COUNT[i] - (DLY_CNT1));
//if(BIT_TEST(DLY,16))
// DLY *= -1;
break;
}
}
return (DLY);
}
void init_CPU()
{
/**************** PORT SETTINGS ***********************/
PORT_A_PULLUPS(FALSE);
SET_TRIS_A(0X1B); // I/P = RA0,RA1,RA3. O/P = RA2,RA4,RA5.
SET_TRIS_C(0X18); // I/P = RC4. O/P = RC0,RC1,RC2,RC5.
/**************** COMPARATOR SETTINGS ***************/
SETUP_COMPARATOR(NC_NC_NC_NC);
/*************** END OF CPU INIT ******************/
}
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_________________
Thank You,
With Best Regards,
Deepak. |
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Ttelmah
Guest
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| Posted: Fri Apr 06, 2007 2:18 am |
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How big isa 'BYTE'?...
What is the biggest number that can fit in this?...
int16 const...
Best Wishes |
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deepakomanna
Joined: 06 Mar 2007
Posts: 92
Location: Pune,India
|
| getting garbage data by using "byte const " |
| Posted: Fri Apr 06, 2007 2:52 am |
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soory sir,
at 1st i couldn't understand the meaning of "BYTE CONST ".
but ,PLZ Refer following code......
| Code: |
#include <16F684.h>
#fuses INTRC_IO,NOWDT,PUT,NOMCLR,PROTECT,NOCPD,NOBROWNOUT,NOPROTECT,NOIESO,NOFCMEN
//Internal RC Osc, no CLKOUT,No Watch Dog Timer,Power Up Time ON,Internal MCLR,Code Protect ON,No EE protection,Brownout detect OFF,
#use delay(clock=8000000)
void init_CPU();
unsigned int16 CALCULATION_FUNCTION(unsigned int16);
unsigned int16 DLY_CNT,RPM_CNT;
void main()
{
int8 j =0;
init_CPU();
while(j != 12)
{
RPM_CNT = 6500;
DLY_CNT = CALCULATION_FUNCTION(RPM_CNT);
RPM_CNT += 500;
j++;
}
}
unsigned int16 CALCULATION_FUNCTION(unsigned int16 TIMER_COUNT)
{
/***** Value in watch window getting different when "using const " **/
//const unsigned int16 RPM_COUNT[14] = {7500,6000,5000,4839,3571,3333,3000,2727,2308,2143,2000,1875,1765,1667};
//const signed int8 SLOPE[13] = {89,1,-106,4,24,3,3,3,-16,-95,11,-102,18};
//const int16 DELAY_COUNT[13] = {542,17,14,81,60,37,33,30,21,25,79,83,120};
/*********************************************************
/*******programe works fine without using " const " ********/
unsigned int16 RPM_COUNT[14] = {7500,6000,5000,4839,3571,3333,3000,2727,2308,2143,2000,1875,1765,1667};
signed int8 SLOPE[13] = {89,1,-106,4,24,3,3,3,-16,-95,11,-102,18};
int16 DELAY_COUNT[13] = {542,17,14,81,60,37,33,30,21,25,79,83,120};
/***************************************************/
int8 i;
signed int32 DLY_CNT1;
unsigned int16 DLY = 0;
for(i = 0; i <= 12; i++)
{
if((TIMER_COUNT <= RPM_COUNT[i]) && (TIMER_COUNT >= RPM_COUNT[i + 1]))
{
DLY_CNT1 = RPM_COUNT[i] - TIMER_COUNT;
DLY_CNT1 = (signed int32)(SLOPE[i] * DLY_CNT1); // int32
DLY_CNT1 = (signed int32)DLY_CNT1 >> 8;
DLY = (unsigned int16) (DELAY_COUNT[i] - (DLY_CNT1));
//if(BIT_TEST(DLY,16))
// DLY *= -1;
break;
}
}
return (DLY);
}
void init_CPU()
{
/**************** PORT SETTINGS ***********************/
PORT_A_PULLUPS(FALSE);
SET_TRIS_A(0X1B); // I/P = RA0,RA1,RA3. O/P = RA2,RA4,RA5.
SET_TRIS_C(0X18); // I/P = RC4. O/P = RC0,RC1,RC2,RC5.
/**************** COMPARATOR SETTINGS ***************/
SETUP_COMPARATOR(NC_NC_NC_NC);
/*************** END OF CPU INIT ******************/
}
So, if used "const" the data showing in watch windows is garbage,but i haven't used "const "the prog. works fine.
Plz reply. |
_________________
Thank You,
With Best Regards,
Deepak. |
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Ttelmah
Guest
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| Posted: Fri Apr 06, 2007 4:15 am |
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What are you trying to 'watch'?. You can only 'watch' RAM variables, so if you 'watch' a value that is declared as a constant, expect garbage. Do the numbers actually come out 'right' at the end?.
Constants are 'odd', they are actually a declaration to a program, held in the ROM, which returns the expected value, not directly a 'number' held in the ROM. hence 'watches' cannot be used in relation to these. If you want to 'see' a const value, you have to code like:
| Code: |
int16 dummy;
dummy=RPM_COUNT[0];
//now a 'watch' on 'dummy', will show the RPM_COUNT[0] value.
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Best Wishes |
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