Looking for Enhanced Mid-range PIC ref manual

[Nigel Goodwin]

Yes, it's quite tricky to get the oscillator speeds set correctly - particularly for 32MHz, as it's not just a matter of the config fuses, you have to set registers as well. Here's the C routine for setting mine to 32MHz, generated by MCC.

void OSCILLATOR_Initialize(void)
{
    // NOSC HFINTOSC with 2x PLL; NDIV 1;
    OSCCON1 = 0x10;
    // CSWHOLD may proceed; SOSCPWR Low power;
    OSCCON3 = 0x00;
    // MFOEN disabled; LFOEN disabled; ADOEN disabled; SOSCEN enabled; EXTOEN disabled; HFOEN disabled;
    OSCEN = 0x08;
    // HFFRQ 16_MHz;
    OSCFRQ = 0x05;
    // HFTUN 0;
    OSCTUNE = 0x00;
    // Wait for PLL to stabilise
    while(PLLR == 0)
    {
    }
}

 

[Mike - K8LH]

Thanks, Bob. The '1703 clock setup is rather tame compared to the 15000 and 18000 series. Like Nigel's example, I let MCC setup the clock for me on a 16F15325 project and copied and pasted the settings into my source file.

/*                                                                      *
 *   configure INTOSC for 16-MHz (no PLL)                               *
 *                                                                      */
     OSCCON1 = 0x60;        // hfintosc, ndiv 1
     OSCCON3 = 0x00;        // cswhold may proceed; soscpwr Low power
     OSCEN = 0x00;          // MFOEN,LFOEN,ADOEN,EXTOEN,HFOEN disabled
                            // SOSCEN enabled
     OSCFRQ = 0x05;         // HFFRQ 16-MHz
     OSCSTAT = 0x00;        // MFOR not ready;
     OSCTUNE = 0x00;        // HFTUN 0;

I also wanted bit-level control of the Power Management module control registers which involved a little bit of research. However, now it's easier (for me) to identify and turn individual peripherals on or off.

   void main()
   { PMD0 = 0<<_PMD0_SYSCMD_POSN |  // Clock network 'on'
            1<<_PMD0_FVRMD_POSN  |  // FVR module off
            0<<_PMD0_NVMMD_POSN  |  // NVM module 'on'
            1<<_PMD0_CLKRMD_POSN |  // CLKR module off
            1<<_PMD0_IOCMD_POSN;    // IOC module off

     PMD1 = 1<<_PMD1_NCOMD_POSN  |  // NCO module off
            1<<_PMD1_TMR2MD_POSN |  // TMR2 module off
            1<<_PMD1_TMR1MD_POSN |  // TMR1 module off
            1<<_PMD1_TMR0MD_POSN;   // TMR0 module off
     
     PMD2 = 1<<_PMD2_DAC1MD_POSN |  // DAC1 module off
            1<<_PMD2_ADCMD_POSN  |  // ADC module off
            1<<_PMD2_CMP2MD_POSN |  // C2 module off
            1<<_PMD2_CMP1MD_POSN |  // C1 module off
            1<<_PMD2_ZCDMD_POSN;    // ZCD module off

     PMD3 = 1<<_PMD3_PWM6MD_POSN |  // PWM6 module off
            1<<_PMD3_PWM5MD_POSN |  // PWM5 module off
            1<<_PMD3_PWM4MD_POSN |  // PWM4 module off
            1<<_PMD3_PWM3MD_POSN |  // PWM3 module off
            1<<_PMD3_CCP2MD_POSN |  // CCP2 module off
            1<<_PMD3_CCP1MD_POSN;   // CCP1 module off

     PMD4 = 1<<_PMD4_UART2MD_POSN | // UART2 module off
            1<<_PMD4_UART1MD_POSN | // UART1 module off
            1<<_PMD4_MSSP1MD_POSN | // MSSP1 module off
            1<<_PMD4_CWG1MD_POSN;   // CWG1 module off

     PMD5 = 1<<_PMD5_CLC4MD_POSN |  // CLC4 module off
            1<<_PMD5_CLC3MD_POSN |  // CLC3 module off
            1<<_PMD5_CLC2MD_POSN |  // CLC2 module off
            1<<_PMD5_CLC1MD_POSN;   // CLC1 module off

Gosh, these chips are getting quite sophisticated and it's taking me a lot longer to setup my projects.

Good luck. Have fun.

Cheerful regards, Mike

 

[BobW]

The '1703 clock setup is rather tame compared to the 15000 and 18000 series.

Yes. In the end, there wasn't much to it. The 32 MHz setting was a bit puzzling though, because of 4xPLL setting requirements, that weren't completely obvious. Since this was my first experience with the enhanced midrange line, it was a bit daunting, seeing the large number of various configuration registers. In the end, most of them could be ignored.

I will mention one thing that may save people some problems: Disable the slew rate limiting on the output pins until you're sure that it won't cause any problems. I found that this slowed the rise time too much on some output lines that were used for clocking external devices.

 

[Beau Schwabe]

One gotcha that I'm sure you are aware of, but in case someone else is not, is the speed the internal oscillator defaults to under a reset such as being programmed from an ICSP. In the case of the PIC16F1703 the default speed is 500kHz. I don't use this particular micro, but I have used plenty of others to be aware of this.

"Following any Reset, the IRCF<3:0> bitsof the OSCCON register are set to ‘0111’ and the frequency selection is set to 500 kHz. The user can modify the IRCF bits to select a different frequency."