TMS320VC5507: PLL circuit information

Hi Satoshi-san,

The USB DPLL programming information is clearly described in section 2.4.2 DPLL Operation. It is all about the USB Digital PLL Control Register (USBDPLL --> USB_CLKMD).

void vUSB_initPLL(Uint16 inclk, Uint16 outclk, Uint16 plldiv)
{
    Uint16 pllmult = (outclk * (plldiv+1)) / inclk;

    plldiv &= 0x3u;

    USB_CLKMD &= ~(1<<USB_PLL_ENABLE); // force into BYPASS mode (b4=0)

    while (USB_CLKMD & (1<<USB_PLL_LOCK)); // wait for BYPASS mode to be active

    USB_CLKMD = ((1<<USB_PLL_IOB)|(pllmult<<USB_PLL_MULT)|(plldiv<<USB_PLL_DIV)|
    (plldiv<<USB_PLL_BYPASS_DIV)|(1<<USB_PLL_ENABLE));

    if (pllmult > 1) // if pllmult > 1, wait for PLL mode to be active
    {
        while (!(USB_CLKMD & (1<<USB_PLL_LOCK)));
    }
}

Best regards,

Ming

Hi Ming,

I imagine the DSP has VCO, divider, phase frequency detector,charge pump and loop filter inside the package.

The loop filter is an analog circuit, and the circuit consists of  capacitors and resistors.

I want to know,

1.the schematic diagram of the loop filter

2.those parts value(capacitance value and resistance value)

Best regards,

Satoshi

Hi Satoshi,

I will have to forward your request to the HW apps team for further help!

Best regards,

Ming 

Hi Ming,

I would appreciate it if you would.

Thanks!

Best regards,

Satoshi

Hi Satoshi,

We don't typically provide that level of design information.  The spru596 document should have all the information you need to use the USB PLL.

Thanks,
Mike