4550 osc

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  1. - 21st October 2009, 19:45 #1
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    Default 4550 osc

    I'm a bit new with this chip and I'm having problems with the oscillator settings. Basically, I already have a program and circuit working with the chip and a 4MHz XT.

    The problem is that when I replace the crystal with a 20MHZ HS nothing communicates anymore. Debug and SPI, to be exact.

    I've changed my DEFINE OSC to 20 and made sure the right MHz and Type are selected in melabs programmer. Is there something else I am missing to get the serial ports back to normal speed?

    I'm using MicroCode Studio - PicBasic Pro with the MeLabs USB Programmer.
  2. - 21st October 2009, 22:51 #2
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    First we need some info....What chip body? What compiler version? Is it a 20Mhz crystal or resonator?

    Nick
  3. - 21st October 2009, 23:09 #3
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    18f4550 is the chip, 40 pin dip. I'm using PicBasic Pro 2.46. And it's a quartz crystal.
  4. - 21st October 2009, 23:49 #4
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    have you put capacitors between the oscilator pins and ground?
  5. - 22nd October 2009, 00:07 #5
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    Yes, did that. 22pF

    Reset is high, too.
  6. - 22nd October 2009, 00:41 #6
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    The '4550 supports USB, and the oscillator section has a lot of options. Try the following;
    asm
    __CONFIG _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L

    __CONFIG _CONFIG1H, _FOSC_HSPLL_HS_1H & _FCMEN_OFF_1H & _IESO_OFF_1H

    __CONFIG _CONFIG2L, _PWRT_ON_2L & _BOR_ON_2L & _BORV_2_2L & _VREGEN_ON_2L
    __CONFIG _CONFIG2H, _WDT_OFF_2H
    __CONFIG _CONFIG3H, _MCLRE_ON_3H & _LPT1OSC_OFF_3H & _PBADEN_OFF_3H & _CCP2MX_ON_3H
    __CONFIG _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _ICPRT_OFF_4L & _XINST_OFF_4L & _DEBUG_OFF_4L
    endasm
    define OSC 48 'core running at 48Mhz
    DEFINE DEBUG_REG PORTA 'pin Porta.5 serial out to debug
    DEFINE DEBUG_BIT 5
    DEFINE DEBEG_BAUD 2400
    DEFINE DEBUG_MODE 0 '0 = TRUE, 1 = INVERTED

    This setup works with a 20 Mhz crystal. You will also find more information if you do a search here for 18f4550

    Good Luck,
    Jerry
    If your oscilloscope costs more than your car...
  7. - 22nd October 2009, 00:52 #7
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    ok, cool, thaught i'd ask a stupid question...

    i used the 18F4550 myself and i also use the same OSC so, i'll run through my settings, however, i'm using winpic800 with a JDM programmer...

    OSC: HS oscillator, PLL enabled, HS used by USB
    CPU system clock: 96MHz PLL dev 5
    Oscilator selection: Devide by 5 (20MHz input)
    Vbor: 2.7V
    Brown-out restet: Enabled in hardware only
    Watchdog: 1:32768
    FCMEM enabled
    IESO enabled
    WDTEN enabled
    PWRTEN disabled
    CCP2MX enabled
    PBADEN enabled
    LPT1OSC enabled
    MCLRE disabled
    DEBUG disabled
    STVREN enabled
    LVP enabled
    ICPORT enabled
    XINST enabled
    USBPLL enabled
    VREGEN enabled

    All CP's are disabled
    All EBT's disabled
    All WRT's disabled

    Acording to oshonsoft's pic18 simulator IDE the BASIC code for those options are asfollows...

    Code:
    Define CONFIG1L = 0x3C
Define CONFIG1H = 0xCE
Define CONFIG2L = 0x17
Define CONFIG2H = 0x1F
Define CONFIG3L = 0x00
Define CONFIG3H = 0x07
Define CONFIG4L = 0xE1
Define CONFIG4H = 0x00
Define CONFIG5L = 0x0F
Define CONFIG5H = 0xC0
Define CONFIG6L = 0x0F
Define CONFIG6H = 0xE0
Define CONFIG7L = 0x0F
Define CONFIG7H = 0x40
    Hopefully, some of that will help...
    if not, can you post a screen shot of your programmers config options screen?

    Thanks
  8. - 22nd October 2009, 17:32 #8
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    Hmm, I was hoping I wouldn't have to learn what a .asm file was...
  9. - 22nd October 2009, 18:25 #9
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    Quote Originally Posted by MyBuddy View Post
    Hmm, I was hoping I wouldn't have to learn what a .asm file was...
    What ASM?
    This is all about setting the configs like you would with any PIC.
    Dave
    Always wear safety glasses while programming.
  10. - 22nd October 2009, 20:00 #10
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    MyBuddy,
    I just noticed that you are new here. Welcome.

    Here is a must read.
    http://www.picbasic.co.uk/forum/showthread.php?t=543
    Dave
    Always wear safety glasses while programming.
  11. - 22nd October 2009, 20:06 #11
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    Quote Originally Posted by MyBuddy View Post
    Hmm, I was hoping I wouldn't have to learn what a .asm file was...
    This has nothing to do with ASM (assembler)
    Take a screen cap of your programmer screen with all your osc config options on and i'll look see if you have anything set wrong...

    :edit
    I've just sorted out my fuse options for use with MPASM... Been meaning to do them but couldn't previously be botherd...

    Now, assuming your using MPASM for compiling this needs to be the first line in your BAS file...

    Code:
    @ __config _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L & _FOSC_HSPLL_HS_1H & _FCMEN_ON_1H & _IESO_ON_1H & _PWRT_ON_2L & _BOR_ON_2L & _BORV_2_2L & _VREGEN_ON_2L & _WDT_ON_2H & _WDTPS_32768_2H & _MCLRE_OFF_3H & _LPT1OSC_ON_3H & _PBADEN_OFF_3H & _CCP2MX_ON_3H & _STVREN_OFF_4L & _LVP_OFF_4L & _ICPRT_OFF_4L & _XINST_ON_4L & _DEBUG_OFF_4L & _CP0_OFF_5L & _CP1_OFF_5L & _CP2_OFF_5L & _CP3_OFF_5L & _CPB_OFF_5H & _CPD_OFF_5H & _WRT0_OFF_6L & _WRT1_OFF_6L & _WRT2_OFF_6L & _WRT3_OFF_6L & _WRTB_OFF_6H & _WRTC_OFF_6H & _WRTD_OFF_6H & _EBTR0_OFF_7L & _EBTR1_OFF_7L & _EBTR2_OFF_7L & _EBTR3_OFF_7L & _EBTRB_OFF_7H
    The list of fuse options avaliable for MPASM can be found in C:\Program Files\Microchip\MPASM Suite
    The INC file for the pic contains the fuse options, so for the 18F4550 you need to open the file C:\Program Files\Microchip\MPASM Suite\P18F4550.INC in notepad or Microcode studio or with MPLAB...
    If you don't know what the options are for, thats where searching the datasheet comes in...
    Last edited by comwarrior; - 22nd October 2009 at 20:49.
  12. - 23rd October 2009, 05:07 #12
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    Quote Originally Posted by mackrackit View Post
    What ASM?
    This is all about setting the configs like you would with any PIC.
    I was confused with the post from b1arrrk, my bad.

    I think this pic is overly complex ... or I'm overly simple.

    Alright, I'm understanding a little better the fuses, but they look exactly like the options in the MeProg Programmer for this chip ... I'm fairly sure I've tried every possible combination of pertinent bits.

    Comwarrior, I understand what you're saying now, but I am getting some funny errors now:
    Code:
    Symbol not previously defined (_MCLR)
Argument out of range (not a valid config register address)
    I'm guessing that second one is because of the first error. As for the first error, I don't get it... I copied the config bit from the .inc then pasted it over the @ line. Do I need to have line breaks after some point or something?
  13. - 23rd October 2009, 05:13 #13
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    Another thing:

    After I compile with the following config bits:
    Code:
    @ __config _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L &
 _FOSC_HS_1H & _FCMEM_ON_1H & _IESO_ON_1H & _PWRT_ON_2L & 
_BOR_OFF_2L & _BORV_21_2L & _VREGEN_ON_2L & _WDT_ON_2H & 
_WDTPS_32768_2H & _MCLRE_ON_3H & _LPT1OSC_ON_3H & _PBADEN_OFF_3H 
& _CCP2MX_ON_3H & _STVREN_OFF_4L & _LVP_OFF_4L & _ICPRT_OFF_4L & 
_XINST_ON_4L & _DEBUG_OFF_4L & _CP0_OFF_5L & _CP1_OFF_5L & 
_CP2_OFF_5L & _CP3_OFF_5L & _CPB_OFF_5H & _CPD_OFF_5H & 
_WRT0_OFF_6L & _WRT1_OFF_6L & _WRT2_OFF_6L & _WRT3_OFF_6L & 
_WRTB_OFF_6H & _WRTC_OFF_6H & _WRTD_OFF_6H & _EBTR0_OFF_7L & 
_EBTR1_OFF_7L & _EBTR2_OFF_7L & _EBTR3_OFF_7L & _EBTRB_OFF_7H
    ... the MeProg pops up, but I still have to change the config settings on that screen, such as the Oscillator type (it is on HSPLL instead of the HS I have config'ed in the above code).
  14. - 23rd October 2009, 05:13 #14
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    Maybe this will help. I set the configs in code so the *.inc is commented out.
    Below is for a 4550 with a 4Mhx external clocking at 48
    Code:
    DEFINE OSC 48
    @ __CONFIG   _CONFIG1L, _PLLDIV_1_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
    @ __CONFIG   _CONFIG1H, _FOSC_HSPLL_HS_1H
    @ __CONFIG    _CONFIG2H, _WDT_OFF_2H & _WDTPS_512_2H
    @ __CONFIG    _CONFIG3H, _PBADEN_OFF_3H & _MCLRE_OFF_3H 
    @ __CONFIG    _CONFIG4L, _LVP_OFF_4L & _ICPRT_OFF_4L &_XINST_OFF_4L
    MCLR nope, MCLRE...
    Dave
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  15. - 23rd October 2009, 16:32 #15
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    the MeProg pops up, but I still have to change the config settings on that screen, such as the Oscillator type (it is on HSPLL instead of the HS I have config'ed in the above code
    HS with PLL enabled is ok... PLL allows USB to be used at diferent clock speed to the main CPU, it's safe to use with PLL even if you don't use USB
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