SH79F6488PSLASH080PR datasheet(38/152 Pages) SINOWEALTH

38 / 152 page

SH79F6488/SH79F6489

Refer to the Label, system clock is changed between OSC1/OSC2/PLL CLK, the steps below must be done in sequence:

①. When OSCSCLK changed from OSC1 to OSC2, the steps below must be done in sequence:

a. Set OSC2ON = 1 to turn on the OSC2CLK, high frequncy oscillator from XTALX or internal 12MHzRC

b. Wait at least Oscillator Warm-up timer (Refer to Warm-up Timer section for details)

c. Set FS = 1 to select OSC2CLK as OSCSCLK

②. When OSCSCLK changed from OSC2 to OSC1, the steps below must be done in sequence:

a. Set FS = 0 to select 32.768kHz oscillator as OSCSCLK

b. Set OSC2ON = 0 to turn off OSC2CLK, reduce the power consumption of the system

③. When OSCSCLK changed from OSC2 to PLL, the steps below must be done in sequence:

a. Set PLLON = 1 to turn on the 48MHz PLL

b. Wait at least 2ms

c. Set PLLFS =1 to select PLL as OSC2CLK,as OSCSCLK

④. When OSCSCLK changed from PLL to OSC2, the steps below must be done in sequence:

a. Set PLLFS = 0 to select OSC2CLK as OSCSCLK

b. Set PLLON = 0 to turn off PLL, reduce the power consumption of the system

⑤. When OSCSCLK changed from OSC1 to PLL, the steps below must be done in sequence:

a. Set OSC2ON = 1

b. Wait at least Oscillator Warm-up timer (Refer to Warm-up Timer section for details)

c. Set PLLON = 1 to turn on the 48MHz PLL

d. Wait at least 2ms

e. Set PLLFS = 1 to select PLL as OSC2CLK

f. Set FS = 1 to select PLL as OSCSCLK

⑥. When OSCSCLK changed from PLL to OSC1, the steps below must be done in sequence:

a. Set FS = 0 to select 12MHz RC as OSCSCLK

b. Set PLLON = 0 to turn off PLL, reduce the power consumption of the system

c. Set OSC2ON = 0 to turn off OSC2CLK

SH79F6488P/080PR Datasheet(PDF) 38 Page - SINOWEALTH Electronic Ltd