Forums

lowest power for 100 MIPS/16bit, which DSP?

Started by Steven Sanders August 25, 2003
Hello DSP gurus worldwide!

For a portable application, we`re targetting 100MIPS@16bit. Which DSP 
can achieve the lowest possible power consumption for this app? We don`t 
care actually if it`s a 16 or 32 bit processor, we just want the lowest 
power consumption!

Any hints welcome!!! Thanx in advance!

greets,

Steven

"Steven Sanders" <steven.sanders@imec.be> ha scritto nel messaggio
news:3F49CB14.6040508@imec.be...

> For a portable application, we`re targetting > 100MIPS@16bit. Which DSP > can achieve the lowest possible power consumption for this > app?
My guess: TMS320VC5402 or TMS320VC5409 (0.54 mW/MIPS) -- Lorenzo
"Lorenzo" <lorenzol@despammed.com> wrote in message news:<bicmq7$7thhp$1@ID-202895.news.uni-berlin.de>...
> "Steven Sanders" <steven.sanders@imec.be> ha scritto nel messaggio > news:3F49CB14.6040508@imec.be... > > > For a portable application, we`re targetting > > 100MIPS@16bit. Which DSP > > can achieve the lowest possible power consumption for this > > app? > > My guess: TMS320VC5402 or TMS320VC5409 (0.54 mW/MIPS)
Have you checked for Blackfin? JaaC
"Jaime Andres Aranguren Cardona" <jaime.aranguren@ieee.org> ha scritto nel
messaggio news:14a86f87.0308250448.41f8f9cf@posting.google.com...

> > My guess: TMS320VC5402 or TMS320VC5409 (0.54 mW/MIPS) > > > Have you checked for Blackfin?
I haven't found the power dissipation data (a lot of parameters in blackfin datasheet are TBD). Instead, in TI site the power dissipation is put in great evidence, which makes me think it's a distinctive feature of 5000 family. BTW, if you can spend a little more you can also use TMS320VC55x family (0.25W/MIPS). For example C5502 at 200 MIPS costs 11$, while C5409 at 100 MIPS costs 10$. Probably it's worth the cost. -- Lorenzo
Steven Sanders <steven.sanders@imec.be> wrote in message news:<3F49CB14.6040508@imec.be>...
> Hello DSP gurus worldwide! > > For a portable application, we`re targetting 100MIPS@16bit. Which DSP > can achieve the lowest possible power consumption for this app? We don`t > care actually if it`s a 16 or 32 bit processor, we just want the lowest > power consumption! > > Any hints welcome!!! Thanx in advance!
Hint: Which DSP finds its way into 60 odd percent of the world cellphones, running on tiny batteries? Regards, Steve
Lorenzo wrote:
> > "Jaime Andres Aranguren Cardona" <jaime.aranguren@ieee.org> ha scritto nel > messaggio news:14a86f87.0308250448.41f8f9cf@posting.google.com... > > > > My guess: TMS320VC5402 or TMS320VC5409 (0.54 mW/MIPS) > > > > > > Have you checked for Blackfin? > > I haven't found the power dissipation data (a lot of parameters in blackfin > datasheet are TBD). Instead, in TI site the power dissipation is put in > great evidence, which makes me think it's a distinctive feature of 5000 > family. > > BTW, if you can spend a little more you can also use TMS320VC55x family > (0.25W/MIPS). For example C5502 at 200 MIPS costs 11$, while C5409 at 100 > MIPS costs 10$. Probably it's worth the cost. > > -- > Lorenzo
Keith Larson's sig: +------------------------------------------+ |Keith Larson | |Member Group Technical Staff | |Texas Instruments Incorporated | | | | 281-274-3288 | | k-larson2@ti.com | |------------------------------------------+ | TMS320C3x/C4x/VC33 Applications | | | | TMS320VC33 | | The lowest cost and lowest power | | floating point DSP on the planet! | | 500uw/Mflop | +------------------------------------------+ Jerry -- Engineering is the art of making what you want from things you can get. &#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;
Hi Steven

Your question is rather open ended because you really dont indicate what 
kind of application or math you need, nor the total cost goal!

Never the less, if you are interested in Texas Instruments low power 
device, you should probably be looking at the C54xx/C55xx and VC33.  But 
if you need 32 bits, be sure to look into the TMS320VC33 (the device I 
am responsible for).

Power
-----
Using the same power measurement techniques as the C5402, the TMS320VC33
device achieves 1mw/MIP with a clock rate of 75MHz (75MIP) device.  This
is largely due to the fact that both devices are built using the same
CMOS process, and the VC33 being 32 bits, needs to chunk around 2x the
opcode and data width... hence 2x the power.

Regarding leakage, the *faster* C54xx devices are fabricated with the
hotter, faster and therefor leakier transistors.  For the VC33 we have
been mostly interested in the low leakage process and (at least so far)
have not offered the device in the faster process.

Mips/Macs/MFlops
----------------
Both the C54xx and VC33 families perform 1 mac (multiply/accumulate) per
cycle, but with the VC33 being floating point, it is rated in FLOPS per
second rather than MAC's/Sec - hence the 150 MFLOP rating at 500uw/MFLOP.

Comparison
----------
Keep in mind that this is an apple compared to an orange.  The VC33 is a
register based (not accumulator) 32 bit opcode processor that performs
32 bit math (fixed and float).  If the intrinsic 'built-in' capabilities
are exceeded for either processor you will pay dearly in needed clock
rates and power.

The C54xx really shines when it comes to 16 bit data and 16 bit math.
This can be especially important when populating external memory since
1/2 the width often costs 1/2 as much!

However, if you fall outside this box, for example if you need 32x32 bit
multipiplies on the C54xx, you will quickly find yourself chunking along
with many many more 16x16 operations and consuming a lot of memory.
Similarily, dont fall outside the small memory model.

                           C5402   VC33
Regs/Accumulators         2       8 40b float/24 32b integer
Internal SRAM             16Kx16  34Kx32 word (all dual access)
Data width                16      32
Opcode width              16      32
Addressing                16      24
Direct addressing range   7       16
Power mw/MIP              0.5     1.0
Price (high volume)       $4.80   $5.00

C55xx
-----
You might also want to look into the C55xx, but I wont be a lot of help 
here since I mostly know the C54xx and C3x.

The interesting aspect of the C55xx is that it can perform 2 MAC's per 
cycle, so if you can keep it busy, it can really chunk through the data. 
The downside is that it takes a lot more to set this up and keep it 
running, so if you dont *need* it, it can end up costing you.

You will also find that these cores tend to be much leakier, greatly 
effecting any standby power savings you may have in mind.

Best regards,
Keith Larson
---------------------------------------------
Steven Sanders wrote:

Hello DSP gurus worldwide!

For a portable application, we`re targetting 100MIPS@16bit. Which DSP 
can achieve the lowest possible power consumption for this app? We don`t 
  care actually if it`s a 16 or 32 bit processor, we just want the 
lowest power consumption!

Any hints welcome!!! Thanx in advance!

greets,

Steven
+------------------------------------------+
|Keith Larson                              |
|Member Group Technical Staff              |
|Texas Instruments Incorporated            |
|                                          |
| 281-274-3288                             |
| k-larson2@ti.com                         |
|------------------------------------------+
|     TMS320C3x/C4x/VC33 Applications      |
|                                          |
|               TMS320VC33                 |
|    The lowest cost and lowest power      |
|    floating point DSP on the planet!     |
|              500uw/Mflop                 |
+------------------------------------------+


Steven Sanders <steven.sanders@imec.be> writes:

> Hello DSP gurus worldwide! > > For a portable application, we`re targetting 100MIPS@16bit. Which DSP > can achieve the lowest possible power consumption for this app? We > don`t care actually if it`s a 16 or 32 bit processor, we just want the > lowest power consumption! > > Any hints welcome!!! Thanx in advance! > > greets, > > Steven
Steven, You should take a closer look at the Analog Devices Blackfin familly of processors. They target the embedded portable markets with it. Here is the beginning of a press release of theirs: Now available, ADSP-BF533 delivers 600-MHz, 1.2 GMACS operation at 280mW; ADSP-BF531, also available now, sets new price performance level with 300MHz for $4.95. Norwood, MA (March 24, 2003) - Analog Devices, Inc. (NYSE: ADI), a global leader in high-performance semiconductors for signal processing applications, today announced the immediate availability of its next-generation Blackfin processor family that delivers twice the performance and half the power consumption of conventional DSPs and embedded processors. The ADSP-BF533 is a 600-MHz/1.2 billion multiply accumulate operations per second (GMACS) processor. The low-cost ADSP-BF531 operates at 300MHz/600 million multiply accumulate operations per second (MMACS). Both Blackfin processors combine best-in-class digital signal processing performance with microcontroller functionality and embedded operating system support to meet the computational demands and power constraints of todays embedded audio, video and communications applications. look at this numbers v----------------v The processors require only 0.15mW/MMAC at 300 MHz and at 600 MHz performance levels, the power consumption of the ADSP-BF533 is only 280 mW. To optimize the advantages of the Blackfin architectures Dynamic Power Management capability, the new processors integrate an on-chip switching regulator that permits programmable control of the core voltage from 0.7 V to 1.2 V - from a single I/O supply thereby reducing overall system costs and external power supply components. You can read the ompleete press release at: http://www.analog.com/processors/news/pressReleases/2003/Mar24_pressRelease.html -jan johansson