On Jun 15, 2010, at 22:14, m...@gmail.com wrote:
>> What is the context of your question? Do you want to go from 3.3V to
>> 5V or from 5V to 3.3V?
>>
>> Do you already have a board design for your 5509A? Do you need to
>> take the 5V nominal USB voltage down to 3.3V for the DSP?
>>
> The supply voltage of PC is 5v.... Th voltage of the DSP USB is
> 3.3v... If we interface DSP USB with system's USB, will it not
> damage the device?... Since the operating voltage of DSP is 3.3 to
> 3.6v....

It seems like you're saying that you have not designed your board
yet. I suggest that you look on the Texas Instruments site for some
of the reference schematics. They show a number of options for
making a board with USB and the 5509A.

In general, though, USB provides anywhere from 4.0V to 5.25V, and so
it is expected that you place a 3.3V regulator, usually of the LDO
variety, on your circuit board to power 3.3V parts like the DSP. The
DSP wires D+ and D- directly to the USB connector, but the VUSB
signal must only connect to the input of the LDO regulator. From
there, the output of the regulator connects to the DSP. It can be
confusing, since the DSP has multiple 3.3V input pins, including one
specifically for USB. After you've handled the power correctly,
there are also some requirements for the D+ and D- signals, including
series resistance, capacitive filtering, etc.

I think most of your questions will be answered with the schematics
for the evaluation boards.

Brian Willoughby
Sound Consulting

What is the context of your question? Do you want to go from 3.3V to
5V or from 5V to 3.3V?

Do you already have a board design for your 5509A? Do you need to
take the 5V nominal USB voltage down to 3.3V for the DSP?
The supply voltage of PC is 5v.... Th voltage of the DSP USB is 3.3v... If we interface DSP USB with system's USB, will it not damage the device?... Since the operating voltage of DSP is 3.3 to 3.6v....

On Jun 14, 2010, at 22:59, m...@gmail.com wrote:
> Thank you Bill, for suggesting MAX3111, which will better for RS232
> comm... Should i use MAX232 for voltage level shifiting?....

The MAX3111 already incorporates voltage level shifting. You provide
3.3V to the chip and it provides internal +5.5V and -5.5V supplies
for the RS-232. It can withstand RS-232 voltages up to +/-12V in
shutdown, and +/-25V in operation. Why would you need the MAX232?
Is it really necessary to have +/-15V just to communicate with a PC
RS-232?

> Thank you Sound, i am searching for USB support in VB6...

You might also consider developing some code in C, and then interface
that to VB. VB is not typically the first choice for communicating
with hardware.

> Core voltage of USB is 3.3v, then how to convert for PC's 5v?....

What is the context of your question? Do you want to go from 3.3V to
5V or from 5V to 3.3V?

Do you already have a board design for your 5509A? Do you need to
take the 5V nominal USB voltage down to 3.3V for the DSP?

Keep in mind that the MAX3111 has internal voltage boost circuits to
go from +3.3V to +/-5.5V

> How to implement USB communications class device on 5509A?....
>

That's a big question. See the USB specifications and the Texas
Instruments sample code for the 5509A.

Brian Willoughby
Sound Consulting

One of the niceties of the MAX3111 is the fact that it includes the
UART, the SPI interface, and the RS-232 level shifting all in one
product, with low-power draw, from one voltage supply.

Regards,
Bill
> -----Original Message-----
> From: c... [mailto:c...] On
> Behalf Of m...@gmail.com
> Sent: Tuesday, June 15, 2010 2:00 AM
> To: c...
> Subject: [c55x] Re: Interfacing TMS320VC5509A with PC
>
> Thank you so much for your valuable replies.... Thank you
> Bill, for suggesting MAX3111, which will better for RS232
> comm... Should i use MAX232 for voltage level shifiting?....
>
> Thank you Sound, i am searching for USB support in VB6...
> Core voltage of USB is 3.3v, then how to convert for PC's
> 5v?.... How to implement USB communications class device on
> 5509A?....
>

Forget what I said about McBSP and RS-232. I knew there was
something that I was overlooking! The McBSP is synchronous, as Jeff
points out, and that's difficult to interface with asynchronous
RS-232 without supporting hardware. Bill's MAX3111 is probably your
best bet.

Still, my other suggestions to find a USB library for VB6 or even
just implement your C5509A board so that it appears as a standard
serial port will work without any hardware.

Brian Willoughby
Sound Consulting
On Jun 13, 2010, at 20:46, Sound Consulting wrote:
> The C5509A has more than just SPI. The 3 McBSP ports should be
> capable of baud rates and data formats compatible with RS-232. You
> don't need an interface IC, since you could just handle the level-
> shifting with discrete transistors and resistors. But you can also
> search the Texas Instruments and Maxim web sites for an IC that would
> make this easy.
>
> Better yet, you might think of finding USB support for VB6, and that
> might be easier than building hardware.
>
> On the other hand, you could implement a USB communications class
> device on the C5509A, and then your chip will appear as a serial port
> to your PC.
>
> There are lots of options.

Hi,
All these suggestions sound great, what I have done in some of my
projects is add an MSP430F from TI, they are easy to program and come
with a wide range of interfaces (SPI, UART etc), many packages and are
quite cheap. Using an MSP430 offers other functionality like RTC or
System Power Controller. They will run from a cheap 32.768 khz crystal.
-Gwyn

Gwyn Evans
Mobile Video Systems
Drachenseestr. 12
81373 Mchen
+491733510658
On 14.06.2010 18:39, Jeff Brower wrote:
>
> Pradeep-
>
> > I need to interface TMS320VC5509A with PC.... 5509A offers
> > SPI,HPI,USB communication,but i need RS232
> > communication, since it will be easy for read/write operation using
> > VB6.... Is there any specific interface IC
> > to convert avaliable protocol to RS232 protocol?.... Waiting for
> > your reply....
>
> Bill's suggestion of MAX3111 is good. If you happen to have a CPLD
> already on the board, another option is a bit of
> logic to convert from async to sync. On a Xilinx CPLD that might take
> around 50 macrocells. In that case you might
> still need a transceiver or other circuitry for level shift.
>
> -Jeff

Thank you so much for your valuable replies.... Thank you Bill, for suggesting MAX3111, which will better for RS232 comm... Should i use MAX232 for voltage level shifiting?....

Thank you Sound, i am searching for USB support in VB6... Core voltage of USB is 3.3v, then how to convert for PC's 5v?.... How to implement USB communications class device on 5509A?....

Pradeep-

> I need to interface TMS320VC5509A with PC.... 5509A offers
> SPI,HPI,USB communication,but i need RS232
> communication, since it will be easy for read/write operation using
> VB6.... Is there any specific interface IC
> to convert avaliable protocol to RS232 protocol?.... Waiting for
> your reply....

Bill's suggestion of MAX3111 is good. If you happen to have a CPLD already on the board, another option is a bit of
logic to convert from async to sync. On a Xilinx CPLD that might take around 50 macrocells. In that case you might
still need a transceiver or other circuitry for level shift.

-Jeff

Pradeep,

I've had a lot of success with the MAX3111. It has a SPI interface on
one side, and full RS-232 on the other, and is powered with a single
3.3V supply.

Regards,
Bill

> -----Original Message-----
> From: c... [mailto:c...] On
> Behalf Of m...@gmail.com
> Sent: Saturday, June 12, 2010 12:41 AM
> To: c...
> Subject: [c55x] Interfacing TMS320VC5509A with PC
>
> Hello,
>
> I need to interface TMS320VC5509A with PC.... 5509A
> offers SPI,HPI,USB communication,but i need RS232
> communication, since it will be easy for read/write operation
> using VB6.... Is there any specific interface IC to convert
> avaliable protocol to RS232 protocol?.... Waiting for your reply....
> Regards
> Pradeep
>