m5m51016btp Renesas Electronics Corporation., m5m51016btp Datasheet - Page 135

• Manufacturer Part Number: m5m51016btp
• Description: Renesas 16-bit Single-chip Microcomputer M16c Family / M16c/20 Series
• Manufacturer: Renesas Electronics Corporation.

M30245 Group
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
2.7.3 Precautions for Frequency synthesizer
(1) Bits 6 and 5 of frequency synthesizer control register are set to (bit6, bit5)=(1, 1) at reset. When using
(2) Set f
(3) The value of f
(4) When the frequency synthesizer is enabled, do not use the output of the frequency synthesizer until
(5) When using the frequency synthesizer, connect a low pass filter to the LPF terminal.
(6) The following setup for the frequency synthesizer should be done after hardware resest.
the frequency synthesizer, we recommended to set to (bit6, bit5)=(1, 0).
after a 2~5ms delay. That will stabilize the output. Also, after the frequency synthesizer has been
enabled, because the output is temporarily (2-5ms) unstable, the contents of none of the registers
should be changed.
1. Cancel the protect register.
2. Set the frequency synthesizer related registers to generate the 48MHz clock that is necessary for
3. Enable the frequency synthesizer by setting frequency synthesizer control register.
4. The protect register should be set to write disabled. A 3ms wait is necessary.
5. The frequency synthesizer locked status bit should be checked. It is necessary to recheck after a
6. Enable USB clock.
7. After waiting four cycles of the f or greater, the USB enable bit should be set to “1”.
the f
wait of 0.1ms if it is “0” (unlocked).
operations.
A minimum delay of 250ns is needed before performing any other USB related registers read/write
SYN
USB
to 12 MHz or lower.
.
PIN
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should not be set below 1 MHz.
2. Frequency synthesizer (PLL)