Hi,
Little follow-up on my own post.
Tried the same code on the 18f452 (with some small changes to the config to
make it run). Thistime using SDCC 2.7.0, as the 2.8 snapshot i was using
complained about missing _usart functions.
It runs as it should. Compiling the code for the 18f4520 using SDCC 2.7.0
still doesn't work.
Any ideas?
Thanks,
-Bastiaan van Kesteren
On Monday 13 October 2008 14:39:19 Bastiaan van Kesteren wrote:
> Hi,
>
> I'm working on a project using the 18f4520, and i've ran into a problem. It
> seems that passing an array to a function results in garbage being read in
> the receiving function.
>
> It seems as if the receiving function is using the wrong address to read
> from! I've fiddled with the stack, but this didn't seem to influence the
> problem. I'm now using the latest SDCC snapshot (2.8.4 #5250 (Oct 12 2008))
> and gputils 0.13.6 on Linux. Tried SDCC 2.8.0 with similair results (the
> garbage output was different, but still garbage..) Also tried to build this
> on windows XP on another machine, using the same SDCC snapshot and gputils
> version. No change there.
>
> Some code demonstrating this issue is attached below. I've compiled this
> using
>
> sdcc -mpic16 -p18f4520 main.c
>
> and loading the resulting main.hex file using and ICD2 programmer from
> MPLAB (on the Windows XP machine).
>
> Output on the uart @ 19200 baud should be "[????]", but I get "[??"
> followed by a lot of garbage
>
> Hope anyone can give me some pointers here!
>
> Thanks in advance,
> -Bastiaan van Kesteren
>
> --------------the code:--------------
>
> #include <pic18fregs.h>
> #include <usart.h>
> #include <stdio.h>
>
> /* Initialise a stack of 255 bytes at RAM address 0x300 */
> #pragma stack 0x300 0xFF
>
> /* Baudrate = FOSC/(16(X+1)): 25 = 19200 @ 8MHz */
> #define BAUDRATE 25
>
> /* Oscillator */
> code char at __CONFIG1H _conf0 = _OSC_INTIO67_1H;
>
> /* Watchdog */
> code char at __CONFIG2H _conf2 = _WDT_OFF_2H;
>
> /* Power up timeout and brown out detection enabled */
> code char at __CONFIG2L _conf1 = _PWRT_ON_2L & _BOREN_ON_2L;
> /* MCLR settings */
> code char at __CONFIG3H _conf3 = _MCLRE_OFF_3H;
> /* Low voltage programming disabled, Stack Overflow Reset enabled */
> code char at __CONFIG4L _conf4 = _LVP_OFF_4L & _STVREN_ON_4L;
> /* Code protection disabled */
> code char at __CONFIG5L _conf5 = _CP0_OFF_5L & _CP1_OFF_5L & _CP2_OFF_5L &
> _CP3_OFF_5L; /* EEPROM read protection disabled, code protection boot
> disabled */ code char at __CONFIG5H _conf6 = _CPD_OFF_5H & _CPB_OFF_5H;
> /* Table write protection disabled */
> code char at __CONFIG6L _conf7 = _WRT0_OFF_6L & _WRT1_OFF_6L & _WRT2_OFF_6L
> & _WRT3_OFF_6L; /* EEPROM write protection disabled, table write protect
> boot disabled, config write protect disabled */ code char at __CONFIG6H
> _conf8 = _WRTD_OFF_6H & _WRTB_OFF_6H & _WRTC_OFF_6H; /* Table read protect
> disabled */
> code char at __CONFIG7L _conf9 = _EBTR0_OFF_7L & _EBTR1_OFF_7L &
> _EBTR2_OFF_7L & _EBTR3_OFF_7L; /* Table read protect boot disabled */
> code char at __CONFIG7H _conf10 = _EBTRB_OFF_7H;
>
> void serial_init()
> {
> // BAUDCON - baudrate generation control Register
> BAUDCON = 0; // 8 bit baudrate generator, auto-baud disabled
>
> // SPBRG - Baud Rate Generator Register
> SPBRG = BAUDRATE;
>
> // BRGH - High Baud Rate Select Bit
> TXSTAbits.BRGH = 1; // (1 = high speed)
>
> // SYNC - USART Mode select Bit
> TXSTAbits.SYNC = 0; // (0 = asynchronous)
>
> // TRISC - Tri-state Data Direction Register for port C
> // RC6 - 6th pin of port C - used for Serial Transmit
> // RC7 - 7th pin of port C - used for Serial Receive
> TRISCbits.TRISC6 = 0; // (0 = pin set as output)
> TRISCbits.TRISC7 = 1; // (1 = pin set as input)
>
> // SPEN - Serial Port Enable Bit
> RCSTAbits.SPEN = 1; // (1 = serial port enabled)
>
> // TXIE - USART Transmit Interupt Enable Bit
> PIE1bits.TXIE = 0; // (0 = disabled)
>
> // RCIE - USART Receive Interupt Enable Bit
> PIE1bits.RCIE = 1; // (1 = enabled)
>
> // TX9 - 9-bit Transmit Enable Bit
> TXSTAbits.TX9 = 0; // (0 = 8-bit transmit)
>
> // RX9 - 9-bit Receive Enable Bit
> RCSTAbits.RX9 = 0; // (0 = 8-bit reception)
>
> // CREN - Continuous Receive Enable Bit
> RCSTAbits.CREN = 1; // (1 = Enables receiver)
>
> // TXEN - Trasmit Enable Bit
> TXSTAbits.TXEN = 1; // (1 = transmit enabled)
>
> stdout = STREAM_USER;
> }
>
> void init()
> {
> /* Internal oscillator @ 8MHz */
> OSCCON &= 0x8F;
> OSCCON |= 0x70;
>
> /* Disable watchdog */
> WDTCONbits.SWDTEN = 0;
> }
>
> void test_puts(data char *str)
> {
> usart_putc(str[0]);
> while( usart_busy() );
> }
>
> void main(void)
> /*
> The main function:
> Initialises the system, and starts all interrupt based tasks.
> */
> {
> char tekst[2];
> tekst[0]='?';
> tekst[1]=0;
>
> init();
>
> serial_init();
>
> while(1) {
> usart_putc('[');
> while( usart_busy() );
>
> /* (1): Send single character; works */
> usart_putc('?');
> while( usart_busy() );
>
> /* (2): Send characters from array; works */
> usart_putc(tekst[0]);
> while( usart_busy() );
>
> /* (3): Pass array to function, which sends them as (2) does; not
> working, sending garbage */ test_puts(tekst);
> while( usart_busy() );
>
> /* (4): send string using the library-functions; not working,
> infinite loop */ usart_puts("?");
> while( usart_busy() );
>
> usart_putc(']');
> while( usart_busy() );
> }
> }
>
>
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's
> challenge Build the coolest Linux based applications with Moblin SDK & win
> great prizes Grand prize is a trip for two to an Open Source event anywhere
> in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/
> _______________________________________________
> Sdcc-user mailing list
> Sdcc-user@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/sdcc-user
-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Sdcc-user mailing list
Sdcc-user@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/sdcc-user
