SH79F6488PSLASH080PR datasheet(37/152 Pages) SINOWEALTH

Part #	SH79F6488P/080PR

Description	Enhanced 8051 Microcontroller with 20bit Σ-ΔADC and LCD Driver

PDF	152 Pages

Scroll/Zoom	100%

Manufacturer	SINOWEALTH [SINOWEALTH Electronic Ltd]

Direct Link	https://en.sinowealth.com

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37 / 152 page

SH79F6488/SH79F6489

7.5.5 System Clock Select

1. If code option OP_OSC is 0000, Below for two clocks to be selected.

OSC1: internal 12MHzRC

OSC2: 48MHz PLLCLK 1/2 prescaler

OSC1:

12MHz RC

OSC2:

PLL CLK : 24M

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

a. Set OSC2ON = 1

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

c. Wait at least 2ms

d. Set PLLFS=1 to select PLL as OSC2CLK

e.Set FS = 1 to select PLL as OSCSCLK

②When 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

2. If code option OP_OSC is 1010 or 1101, Below for three clocks to be selected.

OSC1:32.768kHz oscillator from XTAL

OSC2: high frequncy oscillator from XTALX or internal 12MHzRC

PLLCLK:48MHz PLLCLK 1/2 prescaler

OSC1:

32.768kHz Crystal

OSC2:

12MHz RC or

400kHz~16MHz Crystal

PLL CLK :

24M

SH79F6488P/080PR Datasheet(PDF) 37 Page - SINOWEALTH Electronic Ltd