Oscillator setup MX7ck

Created Tue, 03 Jun 2014 17:39:36 +0000 by black_manta

black_manta

Tue, 03 Jun 2014 17:39:36 +0000

Hi,

I posted previously about a board running slow, and while I follow the example code for setting up the PLLs, I'm still not sure if I'm doing it right. to verify that I had done it right, I tried setting the oscillator output, so I can measure the Fcy frequency with a scope.

has anyone set up the PLLs and OSCIOFNC using MPlab-X? here is what I'm doing:

#pragma config FNOSC = PRIPLL // Oscillator selection #pragma config POSCMOD = EC // Primary oscillator mode #pragma config FPLLIDIV = DIV_2 // PLL input divider #pragma config FPLLMUL = MUL_20 // PLL multiplier #pragma config FPLLODIV = DIV_1 // PLL output divider #pragma config FPBDIV = DIV_8 // Peripheral bus clock divider #pragma config FSOSCEN = OFF // Secondary oscillator enable

#pragma config OSCIOFNC = ON // Clock output on OSCO pin enable

majenko

Tue, 03 Jun 2014 18:03:24 +0000

These are all the #pragma settings from the bootloader source for the Cerebot MX7cK:

//*    Oscillator Settings
    #pragma config FNOSC        = PRIPLL                            // Oscillator selection
    #pragma config POSCMOD      = XT                                // Primary oscillator mode
    #pragma config FPLLIDIV     = DIV_2                             // PLL input divider
    #pragma config FPLLMUL      = MUL_20                            // PLL multiplier
    #pragma config FPLLODIV     = DIV_1                             // PLL output divider
    #pragma config FPBDIV       = DIV_1                             // Peripheral bus clock divider
    #pragma config FSOSCEN      = OFF                               // Secondary oscillator enable

    //*    Clock control settings
    #pragma config IESO         = OFF                               // Internal/external clock switchover
    #pragma config FCKSM        = CSDCMD                            // Clock switching (CSx)/Clock monitor (CMx)
    #pragma config OSCIOFNC     = OFF                               // Clock output on OSCO pin enable

    //*    Other Peripheral Device settings
    #pragma config FWDTEN       = OFF                               // Watchdog timer enable
    #pragma config WDTPS        = PS1024                            // Watchdog timer postscaler

    //*    Code Protection settings
    #pragma config CP           = OFF                               // Code protection
    #pragma config BWP          = OFF                               // Boot flash write protect
    #pragma config PWP          = OFF                               // Program flash write protect

    //*    Debug settings
    #pragma config ICESEL       = ICS_PGx1                          // ICE pin selection

    //*    Other Peripheral Device settings
    #pragma config FSRSSEL      = PRIORITY_7                        // SRS interrupt priority
    #pragma config FCANIO       = OFF                               // Standard/alternate CAN pin select (OFF=Alt)
    #pragma config FETHIO       = ON                                // Standard/alternate ETH pin select (OFF=Alt)
    #pragma config FMIIEN       = OFF                               // MII/RMII select (OFF=RMII)

    //*    USB Settings
    #pragma config UPLLEN       = ON                                // USB PLL enable
    #pragma config UPLLIDIV     = DIV_2                             // USB PLL input divider
    #pragma config FVBUSONIO    = OFF                               // VBUS pin control
    #pragma config FUSBIDIO     = OFF                               // USBID pin control

Just changing the OSCIOFNC=OFF to OSCIOFNC=ON should achieve what you want.

I notice those settings are using the XT (crystal) setting, not the EC (External Clock) setting. Keith / Brian - can you confirm that's right / wrong? Are current MX7cK boards shipping with external clocks or with crystals?