[经验]

MSP430提供的USB官方例程里有一句语法看不懂？

2018-3-31 00:08:51

3098

MSP430提供的USB官方例程里有一句语法看不懂？求指教！！！里面时钟具体是怎么配置的？我只看见一句话USBHAL_initClocks(8000000); // Config clocks. MCLK=SMCLK=FLL=8MHz; ACLK=REFO=32kHz，这句话如何理解？？？
具体程序例程见下面：
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/*
* ======== main.c ========
* "Simple Send"
*
* This example shows a very simplified way of sending.  This might be used in
* an application where the main functionality doesn't change much if a USB
* host is present or not.  It simply calls USBCDC_sendDataInBackground(); if no
* host is present, it simply carries on.
*
* Simply build, run, and attach to a USB host.  Run a terminal application
* and open the COM port associated with this device.  (In Windows, check the
* Device Manager.)  The time should be displayed, every second.
*
* Note that this code is identical to example H9, except for one line of
* code:  the call to USBCDC_sendDataInBackground() instead of
* USBHID_sendDataInBackground().  This reflects the symmetry between writing
* MSP430 code for CDC vs. HID-Datapipe.
*
*+----------------------------------------------------------------------------+
* Please refer to the MSP430 USB API Stack Programmer's Guide, located
* in the root directory of this installation for more details.
* ---------------------------------------------------------------------------*/

#include
#include "driverlib.h"

#include "USB_config/descriptors.h"
#include "USB_API/USB_Common/device.h"
#include "USB_API/USB_Common/u***.h"                   //USB-specific functions
#include "USB_API/USB_CDC_API/U***Cdc.h"
#include "USB_app/u***Constructs.h"

/*
* NOTE: Modify hal.h to select a specific evaluation board and customize for
* your own board.
*/
#include "hal.h"

// Function declarations
void convertTimeBinToASCII(uint8_t* timeStr);
void initRTC(void);

// Application globals
volatile uint8_t hour = 4, min = 30, sec = 00;  // Real-time clock (RTC) values.  4:30:00
volatile uint8_t bSendTimeToHost = FALSE;    // RTC-->main():  "send the time over USB"
uint8_t timeStr[9];                   // Stores the time as an ASCII string

/*
* ======== main ========