https://community.nxp.com/t5/MPC5xxx/MCP5775-SDPLL-can-t-lock-when-using-external-clock-source/m-p/693758#M8634 <HTML><HEAD></HEAD><BODY><P>Hello,</P><P>I'm using a 3.3v LVCMOS external clock source to drive MPC5775 now. The PLL0 can lock normally, but SDPLL can't lock. The code will always pending on&nbsp;while(AFE.PLLSTS.B.LOCK == 0);&nbsp;</P><P>The PLLSTS register show 0 on bit0, bit1, bit2 and bit15.</P><P>The code can lock correctly on the same board with a crystal. The only difference on code is &nbsp;AFE.OSCCTRL.B.EN_EXT setting.</P><P>Would you please let me know that if I missed something to set?</P></BODY></HTML> Fri, 04 Aug 2017 05:19:06 GMT hqliu 2017-08-04T05:19:06Z https://community.nxp.com/t5/MPC5xxx/MCP5775-SDPLL-can-t-lock-when-using-external-clock-source/m-p/693758#M8634 <HTML><HEAD></HEAD><BODY><P>Hello,</P><P>I'm using a 3.3v LVCMOS external clock source to drive MPC5775 now. The PLL0 can lock normally, but SDPLL can't lock. The code will always pending on&nbsp;while(AFE.PLLSTS.B.LOCK == 0);&nbsp;</P><P>The PLLSTS register show 0 on bit0, bit1, bit2 and bit15.</P><P>The code can lock correctly on the same board with a crystal. The only difference on code is &nbsp;AFE.OSCCTRL.B.EN_EXT setting.</P><P>Would you please let me know that if I missed something to set?</P></BODY></HTML> Fri, 04 Aug 2017 05:19:06 GMT https://community.nxp.com/t5/MPC5xxx/MCP5775-SDPLL-can-t-lock-when-using-external-clock-source/m-p/693758#M8634 hqliu 2017-08-04T05:19:06Z