Observe floating data using DataLog module?

Qian,

The DLOG module is coded such that it can buffer data in Q15 format only, it's the user's responsibility to typecast the Q into Q15 in it's main code,

Conversion of an integer to float is not trivial, it's different representation of bits.. hence i would recommend using the optimized IQ math library function, the way we have in the motor control project,

  DlogCh1 = (int16)_IQtoIQ15(clarke1.Bs);

In this case clarke1.Bs is in the global Q format, the global q could be Q24 or float.. when using IQmath header files..

Regards

-Manish Bhardwaj

Hi, Manish

Thank you first.

My DSP is F28335, floating point. So In my code, I should call the header file " IQmathLib.h"?

And in CCS Graph tool configuration, I should choose"16 bit signed integer"or"32 bit floating" in the DSP data type option?

Qian,

Please see a motor control project to see how the data logger is being used, you would have to include the IQmath library and header file.

The project reference can be found here

controlSUITE\development_kits\HVMotorCtrl+PfcKit_v1.6\HVACI_Sensorless_2833x

You would need to choose 16 bit signed integer for data type of the buffer being displayed,

regards

Manish Bhardwaj

Hi, Manish

The data logging module helps me a lot in my project. But here is a new question, my supervisor wants me to plot the figure in matlab instead of printscreen the CCS graph. Is there an easy way to store the data passed to CCS through emulator? Or we can only first store the data in on-chip memory and read the memory in some way, e.g. GEL ?

Can you give me some hints? Thanks

Best wishes,

Qian

Hi, Manish

Your advice did help me! Thanks!

I can't understand why I forgot the 'copy memory' issues.

Best wishes,

Qian

typedef struct{	
	long task; // Variable: Task address pointer float 
	*iptr1; // Input: First input pointer float 
	*dbuff_ptr; // pointer to the location of the data buffer 
	float trig_value; // Input: Trigger point 
	int prescalar; // Parameter: Data log pre scale 
	int skip_cntr; // Variable: Data log skip counter 
	int cntr; // Variable: Data log counter 
	float *write_ptr; // Variable: Graph address pointer 
	int size; // Parameter: Maximum data buffer 
	int current_state; // current state 1= Wait for trigger, 2 = check for rising edge , 3= log data , 4= reset data log 
	int (*init)(); // Pointer to init function 
	int (*update)(); // Pointer to update function 
} DLOG_CH; 

// the init function should update the state to be 1 , i.e. wait for trigger 

DLOG_CH_update() 
{ 
	switch(current_state) 
	{ 
		case 1: // if the value is already greater than the trig value then do not trigger 
				// if the value is smaller than trigger value then wait for rising edge 
				if(*iptr1<trig_value) 
					current_state=2; // wait for the rising edge
				break; 
		case 2: // wait for the rising edge
				if(*iptr1>trig_value) // the value crossed the trigger value in the rising edge
				    current_state=3; // start logging data
				break;
		case 3: skip_cntr++; 
				if(skip_cntr==prescalar) 
				{ 
					// log data 
					*write_ptr=*iptr1; 
					write_ptr++; // move the data buffer pointer to the next location 
					skip_ctr=0; 
					cntr++; 
				} 
				if(cntr==size) 
				{ 
					current_state=4; // finished buffering data for this trigger, reset datalogger 
				} 
				break; 
		case 4: write_ptr=dbuff_ptr; // point the write buffer to the first buffer location 
				cntr=0; 
				current_state=1; // now keep on waiting for trigger 
				break; 
	} 
}

Enclosed is the pseudo code,

This is as far as i can help on this,

Regards

Manish Bhardwaj

Great, I'll check it out and give you some feedback later on.

I was also wondering, is there a way in CCS to get a compilation report of the memory usage ( Flash, Ram etc...) ?  Maybe per type, econst, .text etc?

Yes, look for the map file inside the bunch of files that are generated inside the F2803x_RAM folder inside your project if you are using code provided  by TI

you can use any standard text editor  for viewing this file,

The location for the map file can be specified inside C2000 Linker Options-> Basic Options -> -- map file,

-Manish Bhardwaj

Mr. Bhardwaj,

Copying the entire region  covered by the DLOG Buffer only allows us to save the instantaneous data to a file (just 1 sample). In order to observe the data throughout the experiment, I need to be able to save the data from multiple (consecutive) instances (as the time goes by in real time). Is this possible via memory browser?

Respectfully

Goksan