HSEROUT at Quarter Rate!

[Gitchie]

Hi All,

Currently using a PIC18LF26K80, and have found the HSEROUT command to outputing data at quarter of the specified rate.

Here is the header to my code:

#config
    CONFIG RETEN = OFF              
    CONFIG INTOSCSEL = LOW
    CONFIG SOSCSEL = LOW
    CONFIG XINST = OFF
    CONFIG FOSC = INTIO1
    CONFIG PLLCFG = ON
    CONFIG FCMEN = OFF
    CONFIG IESO = OFF
    CONFIG PWRTEN = OFF
    CONFIG BOREN = OFF
    CONFIG BORV = 0
    CONFIG BORPWR = LOW
    CONFIG WDTEN = OFF
    CONFIG WDTPS = 1
    CONFIG CANMX = PORTC
    CONFIG MSSPMSK = MSK7
    CONFIG MCLRE = OFF
    CONFIG STVREN = OFF
    CONFIG BBSIZ = BB1K
    CONFIG CP0 = OFF
    CONFIG CP1 = OFF
    CONFIG CP2 = OFF
    CONFIG CP3 = OFF
    CONFIG CPB = OFF
    CONFIG CPD = OFF
    CONFIG WRT0 = OFF
    CONFIG WRT1 = OFF
    CONFIG WRT2 = OFF
    CONFIG WRT3 = OFF
    CONFIG WRTC = OFF
    CONFIG WRTB = OFF
    CONFIG EBTR0 = OFF
    CONFIG EBTR1 = OFF
    CONFIG EBTR2 = OFF
    CONFIG EBTR3 = OFF
    CONFIG EBTRB = OFF
#endconfig
'*****
'* Defines and Device Configurations
'*****
define OSC 8                        ' Internal OSC runs at 8MHz
define HSER_RCSTA1 90h              ' Enable USART1 Receiver
define HSER_TXSTA1 20h              ' Enable USART1 Transmitter
define HSER_RCSTA2 90h              ' Enable USART2 Receiver
define HSER_TXSTA2 24h              ' Enable USART2 Transmitter
define HSER_BAUD1 9600
define HSER_BAUD2 9600
TRISA=%00000001                     ' Make PORTA.0 an input
ADCON0=%00000001                    ' Turn on ADC AN0
ADCON1=%00000000                    ' Turn off PORTB ADC's
ADCON2=%00000000                    ' Turn off PORTC ADC's
INTCON=%11000000                    ' Enable Interrupts
PIE1=%00100000                      ' Enable USART1 Interrupt
OSCCON=%01100000
REFOCON=%10100111
OSCTUNE=%10000000

By connecting at 2400 baud, the comms works fine, but I am hoping to find the real reason behind my errors...

Cheers
Mark

[Dave]

what crystal are you driving the PIC with? I notice you have the PLL enabled which will multiply the crystal freq. by 4 times. You have declared the operating frequency as 8 Mhz. If you have set the internal frequency as 8 Mhz then you are generating 24 Mhz. I would check your settings....

[Gitchie]

Thanks Dave,

I am currenty using the internal osc, as set by CONFIG FOSC = INTIO1 and it should be running at 8MHz by the OSCCON=%01100000 configs. In regards to the PLL, by switching it on - by either the PLLCFG or OSCTUNE, it enables the HSEROUT command to operate at the correct baud, but this results in the rest of the pic running at 4 times...

[Dave]

Gitchie, That is because you have declared to PBP that you are running the code @ 8 Mhz. by the statement:
define OSC 8 ' Internal OSC runs at 8MHz

This statement tells PBP to scale all timing statements like PAUSE and the like to use an 8 Mhz. oscillator. You should be setting the DEFINE statement to 32 Mhz. which is the frequency that the processor is actually being clocked at.

[Gitchie]

That's correct, but then the hserout runs at quarter speed... For the moment, I've set the baud to 9600 and will run it at 2400...

[Dave]

Don't you understand? Just set the baudrate to the desired rate and set the DEFINE OSC 32. Everything will work correctly.....

[Gitchie]

Thanks for your replays Dave,

But it was a typographical error with the HSER2 defines... I had HSER_BAUD2 1200 when it should have been HSER2_BAUD 1200

I was hunting for an OSC problem also

Cheers and thanks again for your suggestions