searching for a low power DSP, about 80 MIPS with flash and A/D's

Started by Fonze September 3, 2003
Hello everyone,

So I'm lookig for a DSP with the following characteristics :
- about 80-100 MIPS
- 16 bits fixed point operations
- low-power for embedded application
- on-chip flash (or EEPROM)
- at least 8 12-bits A/D's

As you see, my application doesn't require too much calculation power.
But the problem is I just can't find what I need. All DSPs I find with
all the peripherals are not low-power. And if it is low-power, then it
has nearly no peripheral.

Any good idea?

Thank you

 Fonze
Hi Fonze,

fonzarelli@bonbon.net (Fonze) wrote in message
news:<b5d9b065.0309022346.3eac8a3d@posting.google.com>...
> Hello everyone, > > So I'm lookig for a DSP with the following characteristics : > - about 80-100 MIPS > - 16 bits fixed point operations > - low-power for embedded application > - on-chip flash (or EEPROM) > - at least 8 12-bits A/D's > > As you see, my application doesn't require too much calculation power. > But the problem is I just can't find what I need. All DSPs I find with > all the peripherals are not low-power. And if it is low-power, then it > has nearly no peripheral.
If you are looking for really low power (TI54x in cellphone type low power), you will find this is not very compatible with flash. Ultra low power flash usually only runs up to a few MHz. Fast flash is not so efficient. There are fairly low power flash DSPs in the speed ramge you are looking for. I think the TI 28xx family meets your other requirements. Regards, Steve
fonzarelli@bonbon.net (Fonze) wrote in message
news:<b5d9b065.0309022346.3eac8a3d@posting.google.com>...
> Hello everyone, > > So I'm lookig for a DSP with the following characteristics : > - about 80-100 MIPS > - 16 bits fixed point operations > - low-power for embedded application > - on-chip flash (or EEPROM) > - at least 8 12-bits A/D's > > As you see, my application doesn't require too much calculation power. > But the problem is I just can't find what I need. All DSPs I find with > all the peripherals are not low-power. And if it is low-power, then it > has nearly no peripheral. > > Any good idea? > > Thank you > > Fonze
Well, it is the analogue peripherals that use all the power - there is nothing much that you can do about it, except turn them off when you don't need them. Cheers, Herman http://www.AerospaceSoftware.com
Hi Fonze,

It seems all of the requriements you listed are subject to a solution
that fits within your power budget, but saying "low power" doesn't
tell us very much other than low power "to you".

What is your power budget?

Regards,

Steve Bradshaw
http://www.traquair.com

On 3 Sep 2003 00:46:02 -0700, fonzarelli@bonbon.net (Fonze) wrote:

>Hello everyone, > >So I'm lookig for a DSP with the following characteristics : >- about 80-100 MIPS >- 16 bits fixed point operations >- low-power for embedded application >- on-chip flash (or EEPROM) >- at least 8 12-bits A/D's > >As you see, my application doesn't require too much calculation power. >But the problem is I just can't find what I need. All DSPs I find with >all the peripherals are not low-power. And if it is low-power, then it >has nearly no peripheral. > >Any good idea? > >Thank you > > Fonze
Well, the project is an embedded application.

Approximately, we'll say that ALL the components mustn't need more
than a average 100mA under 3.6V .

Thank you.

 Fonze

Stephen Bradshaw <sjb@traquair.com> wrote in message
news:<2gvblvkin16pngk7af43mst14ro3ib933v@4ax.com>...
> Hi Fonze, > > It seems all of the requriements you listed are subject to a solution > that fits within your power budget, but saying "low power" doesn't > tell us very much other than low power "to you". > > What is your power budget? > > Regards, > > Steve Bradshaw > http://www.traquair.com > > On 3 Sep 2003 00:46:02 -0700, fonzarelli@bonbon.net (Fonze) wrote: > > >Hello everyone, > > > >So I'm lookig for a DSP with the following characteristics : > >- about 80-100 MIPS > >- 16 bits fixed point operations > >- low-power for embedded application > >- on-chip flash (or EEPROM) > >- at least 8 12-bits A/D's > > > >As you see, my application doesn't require too much calculation power. > >But the problem is I just can't find what I need. All DSPs I find with > >all the peripherals are not low-power. And if it is low-power, then it > >has nearly no peripheral. > > > >Any good idea? > > > >Thank you > > > > Fonze
Hi Fonze

No problem.  Either the VC33 or C5xxx will get you there, but I 
naturally prefer the VC33 since thats my domain :-)

The VC33 core runs at 1.8V and tops out at around 1mA/Mhz running an FFT 
at 100% utilization (most apps fall well below this). Using a 90% 
efficiency switcher to drop the 3.6V down to 1.8V will result in about 
40mA of current.

The core current number also includes the peripherals so all you need to 
account for now is the IO power, which is typically very low unless you 
are banging all address and data lines at max rate, and external devices.

The bottom line here is that as long as the external stuff (logic, 
codecs, op-amps etc...) are not too power hungry, a $5 (you do want high 
  voume pricing?) 32 bit floating point device will work!

The C54xx current numbers are about 1/2 as much, but remember that you 
are also doing 16 bit math and working with 16 bit opcodes.  The bottom 
line is that the miles/gallon can drop when you use an undersized engine!

Best regards,
Keith Larson
------------------------------------------
Fonze wrote:

> Well, the project is an embedded application. > > Approximately, we'll say that ALL the components mustn't need more > than a average 100mA under 3.6V . > > Thank you. > > Fonze
+------------------------------------------+ |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 | +------------------------------------------+
Hello Keith,

Thank you for your interrest.
I allready had a look to the C5xxx family and it seems not too bad.
But for the VC33 family, it seems they don't have enough MIPS for me
as the max value for the VC33 is 75 MIPS, which is a little bit
undersized for me as I don't want to encounter these kind of problems
!

Best regards.

 Fonze

Keith Larson <k-larson2@NOSPAM.ti.com> wrote in message
news:<3F5758EE.2000301@NOSPAM.ti.com>...
> Hi Fonze > > No problem. Either the VC33 or C5xxx will get you there, but I > naturally prefer the VC33 since thats my domain :-) > > The VC33 core runs at 1.8V and tops out at around 1mA/Mhz running an FFT > at 100% utilization (most apps fall well below this). Using a 90% > efficiency switcher to drop the 3.6V down to 1.8V will result in about > 40mA of current. > > The core current number also includes the peripherals so all you need to > account for now is the IO power, which is typically very low unless you > are banging all address and data lines at max rate, and external devices. > > The bottom line here is that as long as the external stuff (logic, > codecs, op-amps etc...) are not too power hungry, a $5 (you do want high > voume pricing?) 32 bit floating point device will work! > > The C54xx current numbers are about 1/2 as much, but remember that you > are also doing 16 bit math and working with 16 bit opcodes. The bottom > line is that the miles/gallon can drop when you use an undersized engine! > > Best regards, > Keith Larson > ------------------------------------------ > Fonze wrote: > > > Well, the project is an embedded application. > > > > Approximately, we'll say that ALL the components mustn't need more > > than a average 100mA under 3.6V . > > > > Thank you. > > > > Fonze > > +------------------------------------------+ > |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 | > +------------------------------------------+
Hi Fonze

The C55xx is a good choice as well, but you never did say what you
really needed to do.

The bottom line here is that you need to carefully consider what can
happen when a 16 bit machine will do should you need more than 16 bit
math, opcodes or address reach.  The bottom line is that this can easily
double, triple... quadruple the MIPs.  So dont get confused with 
MIPS=PERFORMANCE.  The bottom line is that PERFORMANCE=PERFORMANCE.

After you look into this, look carefully at the core current -vs- mips,
and dont forget to look carefully at the leakage current as this can be
quite high in the newer devices.

Another consideration might be the penalty of falling outside the chip.
Large on chip memory is a real plus.  On the other hand, if you need a 
*huge* external memory, the C55xx gets a plus since it has a DRAM 
controller built in.

Hope this helps
Keith Larson
----------------------------
Fonze wrote:

 > Hello Keith,
 >
 > Thank you for your interrest. I allready had a look to the C5xxx
 > family and it seems not too bad. But for the VC33 family, it seems
 > they don't have enough MIPS for me as the max value for the VC33 is
 >  75 MIPS, which is a little bit undersized for me as I don't want
 > to encounter these kind of problems !
 >
 > Best regards.
 >
 > Fonze
 >

+------------------------------------------+
|Keith Larson                              |
|Member Group Technical Staff              |
|Texas Instruments Incorporated            |
|                                          |
| 281-274-3288                             |
| k-larson2@ti.com                         |
|------------------------------------------+
|     TMS320C3x/C4x/VC33 Applications      |
|                                          |
| $150 TMS320VC33 DSK's ARE AVAILABLE NOW  |
|                                          |
|               TMS320VC33                 |
|    The lowest cost and lowest power      |
|    floating point DSP on the planet!     |
|              500uw/Mflop                 |
+------------------------------------------+

Hi Keith,

Thank you very much for your enthusiasm.

I had a glance to your TMS320VC33.
It could effectively be quite easier to develop my application in
floating point, and the TMS320VC33 would be perfect for this.
The problem is it has no peripherals as SPI ports, just one serial.

Best regards

 S.Castoldi



Keith Larson <k-larson2@NOSPAM.ti.com> wrote in message
news:<3F58A496.8090602@NOSPAM.ti.com>...
> Hi Fonze > > The C55xx is a good choice as well, but you never did say what you > really needed to do. > > The bottom line here is that you need to carefully consider what can > happen when a 16 bit machine will do should you need more than 16 bit > math, opcodes or address reach. The bottom line is that this can easily > double, triple... quadruple the MIPs. So dont get confused with > MIPS=PERFORMANCE. The bottom line is that PERFORMANCE=PERFORMANCE. > > After you look into this, look carefully at the core current -vs- mips, > and dont forget to look carefully at the leakage current as this can be > quite high in the newer devices. > > Another consideration might be the penalty of falling outside the chip. > Large on chip memory is a real plus. On the other hand, if you need a > *huge* external memory, the C55xx gets a plus since it has a DRAM > controller built in. > > Hope this helps > Keith Larson > ---------------------------- > Fonze wrote: > > > Hello Keith, > > > > Thank you for your interrest. I allready had a look to the C5xxx > > family and it seems not too bad. But for the VC33 family, it seems > > they don't have enough MIPS for me as the max value for the VC33 is > > 75 MIPS, which is a little bit undersized for me as I don't want > > to encounter these kind of problems ! > > > > Best regards. > > > > Fonze > > > > +------------------------------------------+ > |Keith Larson | > |Member Group Technical Staff | > |Texas Instruments Incorporated | > | | > | 281-274-3288 | > | k-larson2@ti.com | > |------------------------------------------+ > | TMS320C3x/C4x/VC33 Applications | > | | > | $150 TMS320VC33 DSK's ARE AVAILABLE NOW | > | | > | TMS320VC33 | > | The lowest cost and lowest power | > | floating point DSP on the planet! | > | 500uw/Mflop | > +------------------------------------------+
fonzarelli@bonbon.net (Fonze) wrote in
news:b5d9b065.0309100508.5efbb72@posting.google.com: 

> Hi Keith, > > Thank you very much for your enthusiasm. > > I had a glance to your TMS320VC33. > It could effectively be quite easier to develop my application in > floating point, and the TMS320VC33 would be perfect for this. > The problem is it has no peripherals as SPI ports, just one serial. > > Best regards > > S.Castoldi > > >
I think the Blackfin BF531 has been mentioned. It has an SPI port & two full duplex synchronous serial ports. It has a variety of power saving features. -- Al Clark Danville Signal Processing, Inc. -------------------------------------------------------------------- Purveyors of Fine DSP Hardware and other Cool Stuff Available at http://www.danvillesignal.com