PROBLEMS CCS 3.224

[tony]

#include <18f4525.h>
//#include <18f452.h>


#int_tbe
void tbe_isr()
{
disable_interrupts(INT_TBE);
TXREG=0x55;
indByte ++;
enable_interrupts(INT_TBE);
return;
}


void main()

{

while (TRUE)
{
BRG16 = LOW;
SPBRG = 207;
SYNC = HIGH;
SPEN = HIGH;
CSRC = HIGH;
TXIE = HIGH;

TXREG=0x55;
indByte = 0;

while (indByte < 5)
{
TXEN = HIGH;
}
TXEN = LOW;
}

return;
}

This code works BAD with PIC18F452 and doesn't work with PIC18F4525, that is the debugger remains in the loop (while (indByte <5)) with indbyte always = 1 and doesn't go on.
Why?
MPLAB is 7.10 and CCS, just buyed, is 3.224.

Instead with MPLAB 7.10 and CCS 3.174 the code works well with PIC18F452.

Maybe, are there the bugs in ccs 3.224 with 18f4525?

I'd like to have some answers because the Maintenance of PCWH is buyed 21 April 2005 and i didn't use for the previous problems.

Thanks a lot in advance
Tony

[Guest]

BUT CAN YOU HELP ME????

[Ttelmah]

Start by removing the disable/enable interrupt functions in the interrupt handler. These are not needed, and may cause problems.
Get rid of the returns at the end of the functions. Though these should not cause problems, they are unneccesary in C. A return should only be used where there is data to return, or you are exiting a function before it's end.
Add a trap at the end of the main function, to avoid coming off the end of this. This is a difference between writing for C on a command line inside an OS, and writing C for an embedded processor, or for internal low level processor code. In the former case, there is the operating system to 'return' to. In the latter cases, you must never return, unless you have set something up to handle this. In the CCS C, if you drop off the end, the compiler puts a sleep instruction to trap the exit. Without this, depending how it is handling the 'return' you will either generate a stack overflow, or hit the same trap.
Without seeing all your bit definitions for the registers, it is impossible to be sure that you are programming the chip correctly. Why not use the C functions, unless you are sure there is a problem with these, they make support much easier...
Do you really want the USART to be running in synchronous mode?. This will generate a seperate 'clock' line for the data, and will require suitable hardware to handle.
You are not showing any control of the TRIS registers. Since you are not using the C functions, controlling these, becomes _your_ responsibility, and the USART will not operate correctly without these setup.
The code as it stands, is full of potential problems. Don't blame the compiler for these.

Best Wishes

[tony]

I have followed yours suggests but the code doesn't work!
The index "indbyte" always = 1 and doesn't go on.

The initial configuration of registers, before to run USART (syncrhronous master mode), is:

TRISC = 0x00;
PIE1 = 0x10;
PIR1 = 0x00;
IPR1 = 0xFF;
PIE2 = 0x00;
PIR2 = 0x00;
IPR2 = 0xDF;
RCSTA = 0x80;
TXSTA = 0x92;
TXREG = 0x00;
RCREG = 0x00;
SPBRG = 0xCF;
SPBRGH = 0x00;
STATUS = 0x04;
INTCON = 0xC3;
INTCON2 = 0xF5;
INTCON3 = 0xC3;

I hope that with this value of registers you can better help me.

Thanks
Tony

[ckielstra]

[Guest]

[Tony]

I must use USART in master synchronous mode and all my code works vey well with 18f452 where the project .hex is obtained through compiler CCS 3.177 & MPLAB 6.60.

The SAME project doesn't work at all with 18f4525 even if #include "18f452.h" as been changed with #include "18f4525.h" but the project.hex is obtained through compiler CCS 3.224 & MPLAB 7.11.

I want to keep the same code by working with 18f4525, therefore i want to investigate the problem.

Maybe 18f4525 is not pin to pin compatible with 18f452????
Then I think the problem is to be find it in compiler CCS 3.224.

Could you please try the code below and let me know whether it is corrrect?

Thank you very much indeed,
Regards
Tony

#include <18f4525.h>

#FUSES HS, NOPROTECT, NOPUT, NOBROWNOUT, NOWDT
#ZERO_RAM

#byte TXREG= 0xFAD
#byte RCREG= 0xFAE
#byte SPBRG= 0xFAF
#byte SPBRGH= 0xFB0
#byte BAUDCON = 0xFB8
#byte RCSTA = 0xFAB
#byte TXSTA = 0xFAC
#byte PIE1 = 0xF9D

#bit BRG16 = BAUDCON.3
#bit BRGH = TXSTA.2
#bit SYNC = TXSTA.4
#bit TXEN = TXSTA.5
#bit CSRC = TXSTA.7
#bit SPEN = RCSTA.7
#bit TXIE = PIE1.4



#int_tbe
void tbe_isr()
{
TXREG=0x55;
indByte ++;
}


void main()
{

BRG16 = LOW;
SPBRG = 207;
SPBRGH =0;
SYNC = HIGH;
SPEN = HIGH;
CSRC = HIGH;
TXIE = HIGH;

while (TRUE)
{
TXREG=0x55;
indByte = 0;
while (indByte < 5)
{
TXEN = HIGH;
}
TXEN = LOW;
}
}

[ckielstra]

[dyeatman]

Also, since he is hard coding the registers they may not be register to register compatible or the addresses may be different!

[sseidman]

[tony]

Ok i forgot to copy the routine about the enable/disable interrupts, at any rate the code doesn't work.

Moreover i checked the addresses of registers and are equals.
Ok The 4525 has more analog inputs than the 452 but i use only the usart and it is the same for both.

Could you please try the code below and thanks
Regards
Tony


#include <18f4525.h>

#FUSES HS, NOPROTECT, NOPUT, NOBROWNOUT, NOWDT, NOLVP
#ZERO_RAM

#byte TXREG= 0xFAD
#byte RCREG= 0xFAE
#byte SPBRG= 0xFAF
#byte SPBRGH= 0xFB0
#byte BAUDCON = 0xFB8
#byte RCSTA = 0xFAB
#byte TXSTA = 0xFAC
#byte PIE1 = 0xF9D

#bit BRG16 = BAUDCON.3
#bit BRGH = TXSTA.2
#bit SYNC = TXSTA.4
#bit TXEN = TXSTA.5
#bit CSRC = TXSTA.7
#bit SPEN = RCSTA.7
#bit TXIE = PIE1.4



#int_tbe
void tbe_isr()
{
TXREG=0x55;
indByte ++;
}


void main()
{

BRG16 = LOW;
SPBRG = 207;
SPBRGH =0;
SYNC = HIGH;
SPEN = HIGH;
CSRC = HIGH;
TXIE = HIGH;


while (TRUE)
{
set_tris_c(0x00);
enable_interrupts(GLOBAL);
enable_interrupts(INT_TBE);
TXREG=0x55;
indByte = 0;
while (indByte < 5)
{
TXEN = HIGH;
}
TXEN = LOW;
disable_interrupts(INT_TBE);
}
}

[tony]

I compared the 18f452.h with 18f4525.h and i noted that in 18f4525 there are:

1. Two another pin PIN_A7 and PIN_E3
2. Another #define CCP_PWM
3. Another constants used in setup_uart()
4. Constants used in setup_comparator()
5. Constants used in setup_vref()
6. Another constants used in setup_low_voltage_detector()
7. Another constants used in setup_oscillator()
8. Another constants used in setup_adc_ports()
9. #define INT_COMP and INT_OSCF

At any rate this differences don't influence my code.

I'm waiting your feedback
Thanks
Tony

[sseidman]

[ckielstra]

[tony]

Hi Ckielstra,
i have got a large code and i have to cut and to copy code snippet.
At any rate i have compiled the below code and it works with 452 and NOT with 4525.

Sorry and could you please try the code below and thanks

Tony

#include <18f4525.h>
//#include <18f452.h>

#FUSES HS, NOPROTECT, NOPUT, NOBROWNOUT, NOWDT, NOLVP
#ZERO_RAM

#byte TXREG= 0xFAD
#byte RCREG= 0xFAE
#byte SPBRG= 0xFAF
#byte SPBRGH= 0xFB0
#byte BAUDCON = 0xFB8
#byte RCSTA = 0xFAB
#byte TXSTA = 0xFAC
#byte PIE1 = 0xF9D

#bit BRG16 = BAUDCON.3
#bit BRGH = TXSTA.2
#bit SYNC = TXSTA.4
#bit TXEN = TXSTA.5
#bit CSRC = TXSTA.7
#bit SPEN = RCSTA.7
#bit TXIE = PIE1.4

int indByte;

#int_tbe
void tbe_isr()
{
indByte ++;
TXREG=0x55;
}


void main()
{

BRG16 = 0;
SPBRG = 207;
SPBRGH =0;
SYNC = 1;
SPEN = 1;
CSRC = 1;
TXIE = 1;


while (TRUE)
{
set_tris_c(0x00);
enable_interrupts(GLOBAL);
enable_interrupts(INT_TBE);
TXREG=0x55;
indByte = 0;
while (indByte < 5)
{
TXEN = 1;
}
TXEN = 0;
disable_interrupts(INT_TBE);
}
}