Kinetis Microcontrollers中的主题 Regarding K61 Clocks https://community.nxp.com/t5/Kinetis-Microcontrollers/Regarding-K61-Clocks/m-p/225090#M4385 <HTML><HEAD></HEAD><BODY><P><SPAN style="font-family: Arial, Helvetica, sans-serif; font-size: 10pt;">I am using MK61FN1M0VMJ12 for <BR />my design. I need to run the processor @ 120MHz. Also using DDR2 memory and RMII <BR />ethernet interface of the processor. Please advice on the proper clocking of the <BR />processor. <BR /><BR />I have seen three external oscillator connections: <BR />1. <BR />XTAL0/EXTAL0 <BR />2. XTAL1/EXTAL1 <BR />3. XTAL32/EXTAL32. <BR /><BR />I have connected <BR />a 32.768kHz crystal on the XTAL32/EXTAL32 pins for RTC operation. <BR />What about <BR />the two XTAL pins? <BR />Shall i need to connect both? <BR />What is the exact <BR />crystal/clock value if i need DDR2 &amp; RMII LAN in my application?</SPAN></P></BODY></HTML> Fri, 26 Jul 2013 06:22:03 GMT sithara 2013-07-26T06:22:03Z Regarding K61 Clocks https://community.nxp.com/t5/Kinetis-Microcontrollers/Regarding-K61-Clocks/m-p/225090#M4385 <HTML><HEAD></HEAD><BODY><P><SPAN style="font-family: Arial, Helvetica, sans-serif; font-size: 10pt;">I am using MK61FN1M0VMJ12 for <BR />my design. I need to run the processor @ 120MHz. Also using DDR2 memory and RMII <BR />ethernet interface of the processor. Please advice on the proper clocking of the <BR />processor. <BR /><BR />I have seen three external oscillator connections: <BR />1. <BR />XTAL0/EXTAL0 <BR />2. XTAL1/EXTAL1 <BR />3. XTAL32/EXTAL32. <BR /><BR />I have connected <BR />a 32.768kHz crystal on the XTAL32/EXTAL32 pins for RTC operation. <BR />What about <BR />the two XTAL pins? <BR />Shall i need to connect both? <BR />What is the exact <BR />crystal/clock value if i need DDR2 &amp; RMII LAN in my application?</SPAN></P></BODY></HTML> Fri, 26 Jul 2013 06:22:03 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/Regarding-K61-Clocks/m-p/225090#M4385 sithara 2013-07-26T06:22:03Z Re: Regarding K61 Clocks https://community.nxp.com/t5/Kinetis-Microcontrollers/Regarding-K61-Clocks/m-p/225091#M4386 <HTML><HEAD></HEAD><BODY><P>Hi..</P><P></P><P> Please see below the response from Freescale Technical Serice Request i got,</P><P></P><P><EM>As the RMII clock source is fixed to OSC0ERCLK and must be 50 MHz, so If RMII is applied in your application, XTAL0/EXTAL0 must be used and a 50MHz oscillator is the best choice. For DDR, there are two clocks for this module, one is HCLKs which can be from multiple clock sources (selected by registers in the MCG module, for example, MCG_C11[PLLCS]), but CLK/CLK2x is</EM><BR /><EM>always from the PLL1, so XTAL1/EXTAL1 is also needed for your case, you may use a 15MHz crystal to get the max 150MHz DDR clock.</EM></P><P></P><P>Regards,</P><P>Sithara</P></BODY></HTML> Fri, 26 Jul 2013 07:50:10 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/Regarding-K61-Clocks/m-p/225091#M4386 sithara 2013-07-26T07:50:10Z