CCS/RM48L952: RM48L952

user5269270

Intellectual 705 points

Part Number: RM48L952
Other Parts Discussed in Thread: HALCOGEN, ADS1278

Tool/software: Code Composer Studio

Hello,

In my project, I want to generate PWM Signal of 4 channel.

1. PWM Channel 1 ==> I need to generate 10MHz clock.

2. PWM Channel 2 ==> I need to generate 6KHz clock.

3. PWM Channel 3 ==> I need to generate 1KHz clock.

4. PWM Channel 4 ==> I need to generate 500Hz clock.

3 Input Capture signal need to configure.

Above configuration i tried with RM48L952 board, except PWM channel 1,remaining PWM channels output i can achieve using HALCogen code generation software.
using HALCogen software i can reach maximum upto ~1MHz.

But, in my application i need to get 10MHz of clock which i need to connect with ADS1278.

I have viewed TI forum, i can understood that for better and more frequency generation better to go with HET IDE.

I installed the HET IDE, i dont know how to configure and import that things my project.Can you please guide me how to

make the above configuration to achieve....

if possible kindly share me the code with those configuration. It helpful for me....

Reply me soon as possible......

Regards,
Anand Kumar

over 5 years ago

0 QJ Wang over 5 years ago

TI__Guru**** 197036 points

Hello Kumar,

Per your information, there are more than 8 N2HET instructions to achieve 4 PWMs and 3 captures. The minimum LRP is 10ns (VCLK)*16 (slots in LRP)=160ns. PWM period requires at least 2 LRP, so it is impossible to out an PWM with 10MHz frequency.

I highly recommend to use ECLK to clock ADS1278.

0 user5269270 over 5 years ago in reply to QJ Wang

Intellectual 705 points

Hello Wang,

Thanks you so much for clear explanation.

I will discuss about this to my harware team.

Thanks and Regards,

Anand Kumar.

0 user5269270 over 5 years ago in reply to user5269270

Intellectual 705 points

Hello wang,

we thought of reducing the sampling rate in our application.

can you please tell that , with the above 4 PWM channel and 3 input capture signal.

At least, can i achieve 3 MHz in one of the PWM channel wang...Please tell me how much i can achieve with max timer clock to module .

Regards,

Anand Kumar N S

0 QJ Wang over 5 years ago in reply to user5269270

TI__Guru**** 197036 points

Hello,

Let me assume you use

1. 2 instruction for each PWM signal: ECMP, and MOV64 (each takes 1 cycle) --> total 8 instruction, 8 cycles

2. 2 instructions for each input capture: 2 PCNT instruction (HR share, high resolution) --> total 6 instruction, 6 cycles

4. Other instructions: for example, counter, BR, etc --->assume 3~4 extra instruction used, 4 instructions,take 4 cycles (might be >4 cycles)

The longest path through an N2HET program must be completed within a loop resolution clock (LRP). Since the longest path or program loop is 8cycles+6cycles+4cycles=18 cycles, we need to chose LR= 32.

If hr=1, LRP= 32/VCLK2 = 32/100MHz = 320 ns

The maximum PWM frequency can be achieved when max in CNT instruction is 1

PWM period = (max+1)*LRP=2*320ns=640ns --> 1.56MHz

If the N2HET code takes less than 16 cycles, you can use LR=16, them max PWM freq will be 3.1MHz.

0 user5269270 over 5 years ago in reply to QJ Wang

Intellectual 705 points

Hello Wang,

Thanks for patients reply wang. If i would have troubled you sry for that.

I can understand that, problem was board design was already completed, they didn't give any connection from ECLK. so only i was asking like that.

Thanks for clear explain.

once again, Thanks for patients reply wang.

Regards,

Anand Kumar.

0 QJ Wang over 5 years ago in reply to user5269270

TI__Guru**** 197036 points

You are welcome. Any question regarding N2HET usage please let us know.

https://training.ti.com/hercules-how-tutorial-using-nhet-generate-pwm

https://www.tij.co.jp/jp/lit/an/spraba0b/spraba0b.pdf?ts=1593270428840&ref_url=https%253A%252F%252Fwww.google.com%252F

https://www.ti.com/lit/an/spna225/spna225.pdf?ts=1593270699413&ref_url=https%253A%252F%252Fwww.google.com%252F

0 user5269270 over 5 years ago in reply to QJ Wang

Intellectual 705 points

Hi Wang,

Thanks for your great support..

Sure, if i get any doubt i will ask.

Have a nice day.. Be safe.

Thanks and Regards,

Anand Kumar.

Arm-based microcontrollers

Arm-based microcontrollers forum

CCS/RM48L952: RM48L952