I use MPC5745R as the main microcontroller.
A 20MHz oscillator is used and 150MHz CPU frequency is then set.
The following code runs correctly.
/************************************************************************************/
/************************************************************************************/
MC_CGM.AC3_SC.B.SELCTL=1; /*PLL0 uses an external oscillator*/
MC_CGM.AC4_SC.B.SELCTL=3; /*PLL1 source is PLL0 PHI1*/
/*20MHz XOSC->160MHz PLL0 PHI*/
/*
PLL0 PHI=Ref/(PREDIV*RFDPHI)*MFD
*/
PLLDIG.PLL0DV.B.RFDPHI = 2;
PLLDIG.PLL0DV.B.PREDIV = 1;
PLLDIG.PLL0DV.B.MFD = 16; /*8->127*/
/*
VCO_PLL0=Ref_PLL0*MFD*2/PREDIV
VCO_PLL0=20MHz*16*2/1=640MHz
*/
/*20MHz XOSC->40MHz PLL0 PHI1*/
/*
PLL0 PHI1=Ref/(PREDIV*RFDPHI1)*MFD
*/
PLLDIG.PLL0DV.B.RFDPHI1 = 8; /*4->15*/
/*40MHz PLL0 PHI1->150MHz PLL1 PHI*/
/*
PLL1 PHI=Ref*MFD/(RFDPHI*2)
*/
/*
VCO_PLL1=Ref_PLL1*MFD
VCO_PLL0=40MHz*30=1200MHz
*/
PLLDIG.PLL1DV.B.RFDPHI = 4;
PLLDIG.PLL1DV.B.MFD = 30;
/*System Clock Selector*/
MC_CGM.SC_DC[0].R = 0x80000000; /*FXBAR=150MHz*/
MC_CGM.SC_DC[1].R = 0x80010000; /*SXBAR=75MHz*/
MC_CGM.SC_DC[2].R = 0x80030000; /*PBRIDGE=37.5MHz*/
/************************************************************************************/
/************************************************************************************/
But if I change the PBRIDGE clock to 50MHz as following:
MC_CGM.SC_DC[2].R = 0x80020000; /*PBRIDGE=50MHz*/
Then my code runs wrong!!!
I don't why!
THe PBRIDGE clock must be half of the slow bar???
Thank you.
