Define oscillator speed

Hello,

I have small project using PIC18F26K22 with 8MHz crystal external oscillator. USART output from PIC is connected over TTL to USB and I use TERMITE serial software to read data from PIC.

I wanna send numbers from 1-255 over USART with a pause of 1 sec.

From pbp manual it state that for every other external oscillator I need to use DEFINE OSC, for my example DEFINE OSC 8.

Code:

---

DEFINE OSC 8

define HSER_BAUD 9600
DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0
DEFINE HSER_CLROERR 1 ' Clear overflow automatically
define HSER2_BAUD 9600
DEFINE HSER2_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER2_TXSTA 20h ' Enable transmit, BRGH = 0
DEFINE HSER2_CLROERR 1 ' Clear overflow automatically

ANSELC = 0


i var word
i = 0
tajmer var byte

start:
    i = i+ 1
    Hserout2 [dec i,13,10]
    pause 1000

goto start

---

Since pause is in millisecond this should give me 1 sec delay. But this delay last to to long over my serial terminal.

I have tried many things and find it only working if I add this line:

Code:

---

#config
 CONFIG FOSC = HSHP
#endconfig

---

When using this confing pause 1000 is really 1 sec. I think with this command I have disabled internal oscillator.

When I look deeper in datasheet it is said that HSHP is best for high power oscillator >16MHz and for oscillators used from 4MHz - 16MHz should be used HSMP.

When I used

Code:

---

#config
 CONFIG FOSC = HSMP
#endconfig

---

again my pause 1000 is not 1 sec.

Any help, advice, correction ?

Thx

default config

Code:

---

#CONFIG
  CONFIG  FOSC = INTIO67
  CONFIG  PLLCFG = OFF
  CONFIG  PRICLKEN = OFF
  CONFIG  FCMEN = OFF
  CONFIG  IESO = OFF
  CONFIG  PWRTEN = OFF
  CONFIG  BOREN = SBORDIS
  CONFIG  BORV = 190
  CONFIG  WDTEN = ON
  CONFIG  WDTPS = 32768
  CONFIG  CCP2MX = PORTC1
  CONFIG  PBADEN = OFF
  CONFIG  CCP3MX = PORTB5
  CONFIG  HFOFST = ON
  CONFIG  T3CMX = PORTC0
  CONFIG  P2BMX = PORTB5
  CONFIG  MCLRE = EXTMCLR
  CONFIG  STVREN = ON
  CONFIG  LVP = OFF
  CONFIG  XINST = OFF
  CONFIG  DEBUG = OFF
  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  WRTD = OFF
  CONFIG  EBTR0 = OFF
  CONFIG  EBTR1 = OFF
  CONFIG  EBTR2 = OFF
  CONFIG  EBTR3 = OFF
  CONFIG  EBTRB = OFF
#ENDCONFIG

---

Quote:

---

Default output frequency of HFINTOSC on Reset.
HFINTOSC/16 – (1 MHz)(3)

---

DEFINE OSC 8


does absolutely nothing but advise the compiler what freq to base timing calculations on

to use ext xtal

Code:

---

#CONFIG
  CONFIG  FOSC = HSHP
  CONFIG  PLLCFG = OFF
  CONFIG  PRICLKEN = OFF
  CONFIG  FCMEN = OFF
  CONFIG  IESO = OFF
  CONFIG  PWRTEN = OFF
  CONFIG  BOREN = SBORDIS
  CONFIG  BORV = 190
  CONFIG  WDTEN = ON
  CONFIG  WDTPS = 32768
  CONFIG  CCP2MX = PORTC1
  CONFIG  PBADEN = OFF
  CONFIG  CCP3MX = PORTB5
  CONFIG  HFOFST = ON
  CONFIG  T3CMX = PORTC0
  CONFIG  P2BMX = PORTB5
  CONFIG  MCLRE = EXTMCLR
  CONFIG  STVREN = ON
  CONFIG  LVP = OFF
  CONFIG  XINST = OFF
  CONFIG  DEBUG = OFF
  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  WRTD = OFF
  CONFIG  EBTR0 = OFF
  CONFIG  EBTR1 = OFF
  CONFIG  EBTR2 = OFF
  CONFIG  EBTR3 = OFF
  CONFIG  EBTRB = OFF
#ENDCONFIG

---