Usage - NEC V850ES/KE1+ User Manual

5.5.3 Usage

(1) When PLL is used
• After reset has been released, the PLL operates (PLLCTL.PLLON bit = 1), but because the default mode is
the clock-through mode (PLLCTL.SELPLL bit = 0), select the PLL mode (SELPLL bit = 1).
• To set the STOP mode in which the main clock is stopped, or to set the IDLE mode, first select the clock-
through mode and then stop the PLL. To return from the IDLE or STOP mode, first enable PLL operation
(PLLON bit = 1), and then select the PLL mode (SELPLL bit = 1).
• To enable the PLL operation, first set the PLLON bit to 1, wait for 200
To stop the PLL, first select the clock-through mode (SELPLL bit = 0), wait for 8 clocks or more, and then
stop the PLL (PLLON bit = 0).
(2) When PLL is not used
• The clock-through mode (SELPLL bit = 0) is selected after reset has been released, but the PLL is
operating (PLLON bit = 1) and must therefore be stopped (PLLON bit = 0).
Remark The PLL is operable in the IDLE mode. To realize low power consumption, stop the PLL. Be sure
to stop the PLL when shifting to the STOP mode.
CHAPTER 5 CLOCK GENERATION FUNCTION
User's Manual U16896EJ2V0UD
μ
s, and then set the SELPLL bit to 1.
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