MPC5744P Evalution Board for the 144LQFP

[masat]

Hello,

We try to use MPC5744P Evalution Board for the 144LQFP(MPC5744PEVB144UG), But it don't work.

Because 40MHz Clock isn't output.

I seems to the difference the circuit of MPC5744PEVB around 40MHz(Y200) and

the description of MPC5744's Datasheet(P.76).

Is it possible to operate the board by using 40MHz crystal?

Thanks,

Masashi

[lukaszadrapa]

Hi,

yes, it is possible to use 40MHz crystal. It works fine on my board when I use this piece of code:

// Enable XOSC, PLL0, PLL1 and enter RUN0 with PLL1 as sys clk (200 MHz)

void SysClk_Init(void)

    {

          MC_CGM.AC3_SC.B.SELCTL = 0x01;            //connect XOSC to the PLL0 input

          MC_CGM.AC4_SC.B.SELCTL = 0x01;            //connect XOSC to the PLL1 input

          // Set PLL0 to 400 MHz with 40MHz XOSC reference

          PLLDIG.PLL0DV.R = 0x58021014;         // PREDIV =  1, MFD = 20, RFDPHI = 2, RFDPHI1 = 11

          MC_ME.RUN0_MC.R = 0x00130070;            // RUN0 cfg: IRCON,OSC0ON,PLL0ON,syclk=IRC

          // Mode Transition to enter RUN0 mode:

          MC_ME.MCTL.R = 0x40005AF0;            // Enter RUN0 Mode & Key

          MC_ME.MCTL.R = 0x4000A50F;            // Enter RUN0 Mode & Inverted Key

          while (MC_ME.GS.B.S_MTRANS) {};            // Wait for mode transition to complete

          while(MC_ME.GS.B.S_CURRENT_MODE != 4) {};        // Verify RUN0 is the current mode

          // Set PLL1 to 200 MHz with 40MHz XOSC reference

          PLLDIG.PLL1DV.R = 0x00020014;         // MFD = 20, RFDPHI = 2

          MC_ME.RUN_PC[0].R = 0x000000FE;            // enable peripherals run in all modes

          MC_ME.RUN0_MC.R = 0x001300F4;            // RUN0 cfg: IRCON, OSC0ON, PLL1ON, syclk=PLL1

          MC_CGM.SC_DC0.R = 0x80030000;    // PBRIDGE0/PBRIDGE1_CLK at syst clk div by 4 ... (50 MHz)

          // Mode Transition to enter RUN0 mode:

          MC_ME.MCTL.R = 0x40005AF0;            // Enter RUN0 Mode & Key

          MC_ME.MCTL.R = 0x4000A50F;            // Enter RUN0 Mode & Inverted Key

          while (MC_ME.GS.B.S_MTRANS) {};            // Wait for mode transition to complete

          while(MC_ME.GS.B.S_CURRENT_MODE != 4) {};        // Verify RUN0 is the current mode

}

You can generate this initialization code by this tool:

Excel MPC5744P Clock Configurator

Regards,

Lukas

[masat]

Thank you for your answer !

But it is hardware problem I want to question.

Do MPC5744P need the circuit in MPC5744P Data Sheet(Rev.0.3 06/2012) 3.11 Figure5 (P.76)

for using 40MHz crystal ?

Regards,

Masashi.

[lukaszadrapa]

Hi,

first of all, I would recommend to download latest version of datasheet (rev 5):

http://www.nxp.com/files/32bit/doc/data_sheet/MPC5744P.pdf

As shown in the Figure 5, just two decoupling capacitors should be used. I can see that the capacitors are not used on this board - I guess that it is due to large parasitic capacitance. EVB board is not supposed to be production design because it allows us to configure different settings. We can use 40MHz crystal, 8MHz crystal, external clock... So, the design is not optimized for best performance but rather for flexibility. Longer signal paths inserts parasitic capacitance, so the external capacitors C1 and C2 are not needed in this case.

Crystal is not running automatically after reset, it is necessary to turn it on. So, it is also matter of software. Have you turned it on or not?

Lukas