TMS320C6657: CPU utilization for Power spreadsheet

Kzk

Part Number: TMS320C6657

Hello,

Could you tell me what value I should enter for CorePac Util in Power Spreadsheet (Excel)? In my application, the time ratio of CPU utilization is SP=40%, CC=40% and IDLE=20% roughly. SP has 4 parallel instructions on average which are half of 8 parallels. I guess I should not set SP to 40%. Please tell me what value I should enter to SP and CC.

The application note (SPRABI5A) has the following description.

% Signal Processing (SP) Utilization is used to represent scenarios with high levels of DSP activity. This corresponds to the case in which all eight instructions fetched by the DSP are executed in parallel each DSP clock cycle, resulting in all eight functional units being active every cycle.

Regards,
Kazu

over 9 years ago

0 Cvetolin Shulev-XID over 9 years ago

TI__Guru 65405 points

Hi Kazu,

I've forwarded this to the design team. Their feedback should be posted here.

BR
Tsvetolin Shulev

0 Senthilkumar Srinivasan over 9 years ago

TI__Mastermind 43660 points

Hello Kazu,

The %SP is when eight functional units are being active every cycle. When it's doing SP but only averaging 4 functional units per cycle this needs to be weighted in the SP %.

Regards,
Senthil

0 Kzk over 9 years ago in reply to Senthilkumar Srinivasan

Genius 5785 points

Hello Senthil,

Thank you for your reply.

In my application, the time ratio of CPU utilization is SP=40%, CC=40% and IDLE=20% roughly.

SenthilKumar Srinivasan said:
The %SP is when eight functional units are being active every cycle. When it's doing SP but only averaging 4 functional units per cycle this needs to be weighted in the SP %.

SP=40%*4/8=20% (Considering the weighting.)

SP=20%, CC=40%, IDLE=40% -> Do I need to enter this value in the spreadsheet?

Regards,
Kazu

0 Mukul Bhatnagar over 9 years ago in reply to Kzk

TI__Guru* 85165 points

Hi Kazu

Since your % IDLE time is 20% , it will more closer if you put SP=20%, CC=60%, IDLE=20%

20% is correct if you think that the IPC is 4 , for the signal processing code.

Processors

Processors forum

TMS320C6657: CPU utilization for Power spreadsheet