L138 ARM and DSP frequency settings

Massimiliano Cialdi

Expert 1995 points

Hi,

I read in L138 Reference Manual that ARM and DSP must have the same frequency (pag. 150, Table 8-1, Note 1).

Is that correct?

best regards

over 12 years ago

0 Rahul Prabhu over 12 years ago

TI__Guru** 116170 points

Yes that is correct. SYSCLK1(Input system clock to DSP) and SYSCLK6 (Input clock to ARM) have a fixed clock ratio of 1:1 so they must operate at the same frequency.

Regards,

Rahul

0 Massimiliano Cialdi over 12 years ago in reply to Rahul Prabhu

Expert 1995 points

what would happen if I tried to change the DSP frequency? For example: DSP runs half of the ARM speed.

best regards

0 Mukul Bhatnagar over 12 years ago in reply to Massimiliano Cialdi

TI__Guru* 83745 points

That scenario is not supported or tested. The design was made with synchronizers in place that expect 1:1 ARM : DSP frequency. Running them asynchronously or running them at different than 1:1 frequency can lead to instability in data movement etc.

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L138 ARM and DSP frequency settings