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how to set maximum clock frequency of 120 MHz in TM4C1294 connected launchpad


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Hello everyone,

 

i want to use TM4C1294 connected launchpad and Energia software for programming. In datasheet it is given that operating frequency is  120MHZ. So how to set it to 120MHz. and how much is by default frequency?

 

Another problem is that i want to handle analog signal up to 40 KHz with the same board. It is having 2 msps sampling rate. So with Energia environment; how much maximum sampling rate can we achieve practically?

 

Please tell me how to change operating frequency using energia code.

 

thanks in advance...

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In Energia the default frequency is 120Mhz.
To change that you don't have any Energia functions.

The maximum with 1 ADC is just 1 msps - you get 2msps if you use both ADCs with advanced techniques.
Not sure on the max speed in Energia. I would say 40Khz is a bit pushing it, maybe you can just about reach it. 

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As @L.R.A mentions, the default CPU frequency is set to 120 MHz. This is done in wiring.c line 64.

 

There is some overhead in analogRead() that will most likely not get you to 40KHz. If you would like to get the max out of the ADC then I would advice to use the driverlib API's and base the implementation on interrupts rather then polling.

 

You can use driverlib calls in Energia directly. Below is a code snip demonstrating how:

#include <stdint.h>
#include "driverlib/adc.h"
#include "driverlib/sysctl.h"
void setup()
{
  SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);  
}

void loop()
{
  
}
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Use void setModule(unsigned long); to select the Serial port or any of the following objects

 

extern HardwareSerial Serial;

extern HardwareSerial Serial1;

extern HardwareSerial Serial2;

extern HardwareSerial Serial3;

extern HardwareSerial Serial4;

extern HardwareSerial Serial5;

extern HardwareSerial Serial6;

extern HardwareSerial Serial7;

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