LPC546x :How to configure External oscillator for USB ports

[AW]

Hi All,

Currently i am using Dual USB port in my system and everything is working on the internal oscillator , now i want to configure only both the USB ports on the external Oscillator, How to proceed with this ?

Any inputs ,suggestions Appreciated!

Regards

AW.  

[Miguel04]

Hi @AW 

You can find the information on User Manual UM10912:

Chapter 7.5.35 USB0 clock source select register.

Chapter 7.5.36 USB1 clock source select register.

Bits 2:0 with a value of 0x2 [USB PLL clock (usb_pll_clk)]

According to Fig 10. Clock generation. The clk_in for USB PLL become usb_pll_clk.

Let me know if you have another question.

Best Regards, Miguel.

[AW]

I want to configure 8MHz External crystal in the existing system and with that USB0 and USB1 should work.
XTALIN and XTALOUT are pin 20 and pin 19 of the LPC54605J512
How to configure the crystal and route the pins appropriately

I am new to this so just trying to understand how to do it.

Can you guide me on same direction ,to proceed further?

[Miguel04]

Hi @AW 

Can you be more specific with "how to route the pins"? To be able to provide you the correct information.

Also, I recommend you to check the datasheet chapter 13.6 XTAL oscillator and Fig 45. Power, clock, and debug connections.

Best Regards, Miguel.

[AW]

Sorry for the confusion, my questions might be silly but,

I was using the MCUXpesso config tool to configure the external clock on pin 19 and 20 but it was not allowing me to configure ,on pins it was showing crossed and it shows grayed so what i meant to route is using that tool it was showing error these pins cannot be routed.

where to configure those pins, which will Enable the oscillator. Do i need to configure PDRUNCFG0 register to enable external clock or PDRUNCFG1 ? if yes then which bit in that register used to configure external clock ?

How to configure External Oscillator and enable it.

Regards , AW

[Miguel04]

Hi @AW 

Thanks for the information, it is usefull.

According to the User Manual on register PDRUNCFG0 [Table 216] bit [PDEN_VD2_ANA] must be powered-up for external crystal oscillator to work. You can verify it on chapters 39.3 and 40.3.

Let me know your questions.

Best Regards, Miguel.