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Frequency-modulated phase locked loop (FMPLL)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
581
lock, the FM parameters are reset and the modulation is disabled until the PLL relocks and the
FMPLL_SYNFMMR is programmed again.
After programming the FM parameters, it takes some time until these parameters get propagated to the
PLL analog circuitry. During this time, the BSY bit gets asserted. The modulation must only be enabled
when the FM parameters have already propagated to the analog circuitry. Therefore, the sequence for
programming FM is:
1. Poll FMPLL_SYNSR[LOCK] until it asserts.
2. Program the MODSEL, MODPERIOD and INCSTEP fields of the FMPLL_SYNFMMR.
3. Poll FMPLL_SYNFMMR[BSY] until it negates.
4. Assert FMPLL_SYNFMMR[MODEN].
Summary of Contents for MPC5644A
Page 2: ...MPC5644A Microcontroller Reference Manual Rev 6 2 Freescale Semiconductor...
Page 24: ...MPC5644A Microcontroller Reference Manual Rev 6 24 Freescale Semiconductor...
Page 26: ...MPC5644A Microcontroller Reference Manual Rev 6 26 Freescale Semiconductor...
Page 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Page 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Page 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
Page 1440: ...FlexCAN Module MPC5644A Microcontroller Reference Manual Rev 6 1440 Freescale Semiconductor...