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Clock Mode Settings Constants

Clock Mode Setting Constants

Clock Mode Setting Constant1

XO Resistance2

XI/XO Capacitance2

Description

RCFAST

Infinite

n/a

Internal fast oscillator (~12 MHz).  May be 8 MHz to 20 MHz. (Default)

RCSLOW

Infinite

n/a

Internal slow oscillator (~20 kHz).  May be 13 kHz to 33 KHz.

XINPUT

Infinite

6 pF (pad only)

External clock-oscillator (DC to 80 MHz); XI pin only, XO disconnected

XTAL1

2 kΩ

36 pF

External low-speed crystal (4 MHz to 16 MHz)

XTAL2

1 kΩ

26 pF

External medium-speed crystal (8 MHz to 32 MHz)

XTAL3

500 Ω

16 pF

External high-speed crystal (20 MHz to 80 MHz)

PLL1X

n/a

n/a

Multiply external frequency times 1

PLL2X

n/a

n/a

Multiply external frequency times 2

PLL4X

n/a

n/a

Multiply external frequency times 4

PLL8X

n/a

n/a

Multiply external frequency times 8

PLL16X

n/a

n/a

Multiply external frequency times 16

Note 1: All constants are also available in Propeller Assembly

Note 2: All necessary resistors/capacitors are included in the Propeller Chip

Propeller Help Version 1.1

Copyright © Parallax Inc.

5/13/2009