msp430x22x4_hfxtal.c

MSP430的开发程序的例子+中文注释

//******************************************************************************
//  MSP430F22x4 Demo - Basic Clock, MCLK Sourced from HF XTAL
//
//  Description: Proper selection of an external HF XTAL for MCLK is shown by
//  first polling the OSC fault until XTAL is stable - only then is MCLK
//  sourced by LFXT1. MCLK/10 is on P1.1 driven by a software loop taking
//  exactly 10 CPU cycles.
//  ACLK = MCLK = LFXT1 = HF XTAL, SMCLK = default DCO ~1.2MHz
//  //* HF XTAL NOT INSTALLED ON FET *//
//  //* Min Vcc required varies with MCLK frequency - refer to datasheet *//
//
//               MSP430F22x4
//            -----------------
//        /|\|              XIN|-
//         | |                 | HF XTAL (3