How to deal w/ SmartReflex design when I have multiple TCI6488 devices on board?

I am not very familiar with the TCI6488 and what it has in regards to SmartReflex, but if it is the same sort of SmartReflex that is available on the OMAP3 processor line than you would have to have a seperate adjustable regulator for each individual device. At least for the OMAP3, the SmartReflex functions entirely by adjusting the voltage the part is being run at based on process variations, temperature, and silicon degredation, meaning it would have potentially a different voltage for each part which can vary over time.

Depending on how this is implemented on the TCI6488 you may be able to take the SmartReflex feedback from multiple devices into a small logic device (perhaps FPGA) and have the voltage from a single regulator set to the lowest common safe/stable voltage for all parts. However if you did something like this than if you had a single device that required a higher voltage for whatever reason than you would have lost the value of the SmartReflex because all the devices would have the same higher voltage so if you have more devices there are diminishing returns from such a shared SmartReflex implementation, if it is even possible.

In general for the TCI6488 you probably want to work with your local TI contact for support.

The datasheet and the Hardware Design Guide both state that "This requires a voltage regulator for each [DSP] device." The Hardware Design Guide includes one recommendation for a way to implement SmartReflex with the PTH08T240F, as you are already aware.

Because SmartReflex keeps the total power consumption at an optimized point for each DSP, your design with 20x DSPs will be substantially aided by this required feature. The addition of a core voltage regulator for each DSP will add to the average board space, but the SmartReflex feature is a very worthwhile feature and worthy of this impact to your board.

The TCI6488 is a specialized part that has limited availability. If you are working with a TI FAE on this design, it might be useful to get some clarification with that FAE on your application and get feedback on your questions on SmartReflex.

Bernie Thompson said:

I am not very familiar with the TCI6488 and what it has in regards to SmartReflex, but if it is the same sort of SmartReflex that is available on the OMAP3 processor line than you would have to have a seperate adjustable regulator for each individual device. At least for the OMAP3, the SmartReflex functions entirely by adjusting the voltage the part is being run at based on process variations, temperature, and silicon degredation, meaning it would have potentially a different voltage for each part which can vary over time.

Depending on how this is implemented on the TCI6488 you may be able to take the SmartReflex feedback from multiple devices into a small logic device (perhaps FPGA) and have the voltage from a single regulator set to the lowest common safe/stable voltage for all parts. However if you did something like this than if you had a single device that required a higher voltage for whatever reason than you would have lost the value of the SmartReflex because all the devices would have the same higher voltage so if you have more devices there are diminishing returns from such a shared SmartReflex implementation, if it is even possible.

In general for the TCI6488 you probably want to work with your local TI contact for support.

Bernie,

Thanks for the tip. As I have no experience on OMAP3, I just wonder whether you folks would be able to disable the SmartReflex, if the fixed power regulator is preferred.

Cheers,

David

RandyP said:

The datasheet and the Hardware Design Guide both state that "This requires a voltage regulator for each [DSP] device." The Hardware Design Guide includes one recommendation for a way to implement SmartReflex with the PTH08T240F, as you are already aware.

Because SmartReflex keeps the total power consumption at an optimized point for each DSP, your design with 20x DSPs will be substantially aided by this required feature. The addition of a core voltage regulator for each DSP will add to the average board space, but the SmartReflex feature is a very worthwhile feature and worthy of this impact to your board.

The TCI6488 is a specialized part that has limited availability. If you are working with a TI FAE on this design, it might be useful to get some clarification with that FAE on your application and get feedback on your questions on SmartReflex.

Randy,

Not quite sure if you have any idea whether the dynamic power management by SmartReflex would have any impact to the DSP performance (such as lower core voltage implies less performance). I was just thinking how things are going to be assuming I have DSP farm composed by 20x DSP devices while some of them may be running at full speed with maximum core voltage (because these devices may reside close to the fan so the ambient temperature is lower) and the rest may be slowing down somehow (throttled by SmartReflex when it senses the external thermal sensor reporting the high temperature).

With the scenario aforementioned, I don't know if different DSP devices would possess different capability (in terms of performance, which may be related to SmartReflex) - something that we may want to avoid as this may demand extra effort  from the load balancing software/middleware when distributing the tasks (such as voice transcoding) to the devices in DSP farm.

Cheers,

David

RandyP said:

The datasheet and the Hardware Design Guide both state that "This requires a voltage regulator for each [DSP] device."

SmartReflex is not an option for the TCI6488. It is a requirement. Separately for each TCI6488 in the DSP farm.