4550 osc

[MyBuddy]

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.

[Macgman2000]

First we need some info....What chip body? What compiler version? Is it a 20Mhz crystal or resonator?

Nick

[MyBuddy]

18f4550 is the chip, 40 pin dip. I'm using PicBasic Pro 2.46. And it's a quartz crystal.

[comwarrior]

have you put capacitors between the oscilator pins and ground?

[MyBuddy]

Yes, did that. 22pF

Reset is high, too.

[b1arrk5]

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

[comwarrior]

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...


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

[MyBuddy]

Hmm, I was hoping I wouldn't have to learn what a .asm file was...:mad:

[mackrackit]

Hmm, I was hoping I wouldn't have to learn what a .asm file was...:mad:
What ASM?
This is all about setting the configs like you would with any PIC.

[mackrackit]

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

[comwarrior]

Hmm, I was hoping I wouldn't have to learn what a .asm file was...:mad:

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...


@ __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...

[MyBuddy]

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:
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?

[MyBuddy]

Another thing:

After I compile with the following config bits:

@ __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).

[mackrackit]

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


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...

[comwarrior]

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