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TMS320C32 => TMS320C33 Porting

Started by Daniel Jose Sandahl October 7, 2003
Hello,

I'm currently on a project in which we are looking to port an existing
program from the TMS320C32 to the TMS320C33.

I was wondering if anyone has run into problems doing a port to the
TMS320C33 platform.

Daniel J. Sandahl



Hi Daniel

Here is a comparison

C32 C31 VC33 Comment
MFlops 80 80 150
Mips 40 40 75
CycleTime 25ns 25 13.3
OnchipRAM 0.5K 2K 34K 32 bit dual access, 68x increase
PLL no no yes
0dly decoder no no yes
ChipTypPwr-mW 2000 2000 100
8/16/32 bus yes no no
Code Compatible yes yes yes
Debug MPSD MPSD JTAG
Serial Ports 1 1 1
DMA channels 2 1 1
Package 132PQFP 132PQFP 144TQFP
Voltage 5V 5V 3.3/1.8
EdgeTrgrInts yes no Yes

If you examine this table you will see that the C32 had two advantages.
That the bus could be configured for narrow external memory and word widths,
and that the DMA had been augmented to handle two channels. However, the
amount of on-chip RAM was rather anemic.

Yet I cant think of too many people have built C32 systems that need all
three data types. If you think about this the VC33 probably has more
on-chip 32 bit RAM than most C32 systems ever had, and if neccessary you can
populate the external RAM with less than 32 bits.

One of the examples I love to point out is the parametric equalizer demo for
the VC33 DSK. When Log Differential Compression is used (LDC is a TI patent
but OK to use on any TI processor) the audio quality is amazingly good even
when the audio data is chopped down to 6 bits and passed through 10 stages
of IIR. Even at this level there is no apparant degradation! What this is
telling us is that by populating the *upper* 16 bits you can use this memory
for a short floating point and you dont have to do much more than that!
And, by the way, the external RAM decode on the VC33 DSK is set up for 32b
width, hi-16 and lo-16... just in case anyone wants to try these experiments.

So why choose to upgrade the C31 instead of the C32? Well, it was decided
that since most of our C3x customers were using C31's, the VC33 should look
as much like the C31 as possible. If you dig under the hood, you will even
find that the peculiar 34K internal words of RAM is actually 2K + 32K.
Basically the original C31 2x1K ram blocks, the bootloader, and the memory
map are identical. All that was done was that the big 32K 'hole' that was
previously reserved internal RAM was filled in.

Best regards,
Keith Larson

-----------
At 09:02 PM 10/7/03 -0000, you wrote:
Hello,

I'm currently on a project in which we are looking to port an existing
program from the TMS320C32 to the TMS320C33.

I was wondering if anyone has run into problems doing a port to the
TMS320C33 platform.

Daniel J. Sandahl
+-----------+
|Keith Larson |
|Member Group Technical Staff |
|Texas Instruments Incorporated |
| |
| 281-274-3288 |
| |
| www.micro.ti.com/~klarson |
|-----------+
| TMS320C3x/C4x/VC33 Applications |
| |
| TMS320VC33 |
| The lowest cost and lowest power 500 w/Mflop |
| floating point DSP on the planet! |
+-----------+