Is it possible to interface DDR2 with K70 with OSC oscillator only? I don't have OSC0 and OSC2 oscillator on board.

[anujsinghvi]

I don't have option to solder OSC0 and OSC1 in my board.

[Paul_Tian]

Hi, Anuj

Do you mean the OSC is a oscillator with VCC and GND pin, not a crystal? If yes, I think you can use this oscillator for both K70 and DDR2 together.

Hope my reply can help you.

Best Regards

Paul

[anujsinghvi]

Hello Paul,

Thanks for your reply.

I've used Crystal 12MHz in between EXTAL1 (P7) and XTAL(R7).  But not have any other crystal on XTAL0-EXTAL0 and XTAL32-EXTAL32 pins in my board.

I am facing issue that DDR clock is not working with it.

K70 Tower board has all 3 crystal and there it is working.

I am not sure whether one crystal is not enough as it is not mentioned anywhere in datasheet as far as i studied.

Please let me know if it is possible.

Regd,

Anuj

[Paul_Tian]

Hi, Anuj

As I mentioned, if you want to share clock source, you need to use oscillator which has VCC and GND pin not a crystal. Then connect oscillator output pin to EXTAL pin.

Hope my reply can help you.

Best Regards

Paul

[sanjeev_kumar]

Hello Paul,

On the Behalf of Anuj I want to give some comments.

We totally agree with you that if I want to share clock source, need of oscillator is compulsory . But in this case scenario is Totally Different.

We are using K70 series MCU to develop one application and we have connected Crystal on Pin EXTAL1 (P7) and XTAL(R7). But if you will refer K70 Development Board(TWR-K70F120M-SCH) crystal is connected on Pin EXTAL1 (P7) and XTAL1(R7), Oscilator is connected on Pin EXTAL0(T15) and 32.768KHz is connected on Pin XTAL32(T6) and EXTAL32(T5).

In our Development board Oscilator and 32.768KHz is not connected which is marked Bold in the above line.

So please let us know whether the DDR operation can be achieved with the crystal mounted on Pin EXTAL1 (P7) and XTAL(R7) without connecting Oscillator and 32.768KHz crystal.

Thanks and Regards,

Sanjeev Kumar

[Paul_Tian]

Hi, Sanjeev

You cannot connect to EXTAL1 but EXTAL0. Ethernet external clocking source is from pin EXTAL0 not EXTAL1. Thanks.

Hope my reply can help you.

Best Regards

Paul

[sanjeev_kumar]

Hi Paul,

Thanks for your quick reply.

So can I use 12MHz of crystal at EXTAL0 instead of 50MHz of oscilator (50MHz of oscilator is used in evaluation board at Port EXTAL0)?

Regards,

Sanjeev Kumar

[Paul_Tian]

Hi, Sanjeev

Sorry, you cannot do in this way. If you use MII mode, please connect 25MHz to EXTAL0. If you use RMII mode, please connect 50MHz to EXTAL0. Thanks.

Hope my reply can help you.

Best Regards

Paul