PL2303 driver guide ?

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View

I am writting a firmware to connect an embedded USB host with the Prolifi
PL2303 USB-RS232 chip. The PL2303 chip is used to get data from som
RS232-enabled devices and then transfer these data to the USB host. Now
need detailed information about PL2303's specification and operation, t
develope the appropriate driver for it.
I have been searching for some PL2303 driver or programming guides bu
haven't found any of them yet.

Has anybody worked with PL2303 ? Please give me some help !

Thanks,
N.L.Trung

Re: PL2303 driver guide ?
Quoted text here. Click to load it

If you are lucky, you *could* get the API from Prolific. FTDI offers a
similar service under NDA.

Meindert



Re: PL2303 driver guide ?

Quoted text here. Click to load it

Thanks Meindert,
May be that API is the exact thing I need now.
Can you tell me how to get the PL2303's API ?

Thank you very much,
N.L.Trung

Re: PL2303 driver guide ?
Quoted text here. Click to load it

Well, here's what I wrote earlier:
Quoted text here. Click to load it
So, contact Prolific...

Meindert




Re: PL2303 driver guide ?
Quoted text here. Click to load it

When I wrote a driver for this chip, I gleaned the apparently
reverse-engineered interface information from the appropriate
Linux device driver.

--
Michael N. Moran           (h) 770 516 7918
5009 Old Field Ct.         (c) 678 521 5460
We've slightly trimmed the long signature. Click to see the full one.
Re: PL2303 driver guide ?
Quoted text here. Click to load it



Hi Michael,

Actually I am writting the PL2303 driver base on some reverse-engineere
information retrieved by monitoring the data transfer process between
PL2303-based USB-RS232 cable and PC. Now I can enumerate the PL2303, se
the COM settings like baudrate, stop bits, parity... I can send as man
data as I like from the embedded USB host to PL2303 as well. But there i
still a big problem because the host cannot get data from PL2303.
Now I need some more information on:
1. How to be notified when there's some data in the Receive buffer o
PL2303.
2. How to know the amount of data in the Receive buffer of PL2303.

Best,
N.L.Trung


Re: PL2303 driver guide ?
Quoted text here. Click to load it

You have to poll the PL2303 for that. Remember, USB is a master/slave system
where a slave NEVER starts transmitting by itself. Transmission of a slave
is always a response to a request from the master.

Meindert



Re: PL2303 driver guide ?

Quoted text here. Click to load it

Thanks Meindert,

I have implemented a polling mechanism to get data from PL2303 to th
embedded host. But there is another problem

According to PL2303's spec, the chip has an 256-byte-buffer for each T
and Rx operation. But when I transfer a large amount of data (about 3KB
to the RS232 interface of PL2303, the USB host can only read a few byte
from the USB interface. It seems that the data in PL2303's buffer has los
so I cannot read all the data transfered to RS232 interface.





Re: PL2303 driver guide ?
Quoted text here. Click to load it

Without knowing all the details, I'd say: poll more often. You have to at
least poll often enough not to let your 256 buffer fill up.

Meindert



Re: PL2303 driver guide ?
"trungnl" ...
Quoted text here. Click to load it


You did read the datasheet and manuals at this site?

  http://www.prolific.com.tw/eng/Download-2.asp?ID17 %

Arie de Muynck




Re: PL2303 driver guide ?

Quoted text here. Click to load it

Yes I did read all the docs at Prolific Website, but they lack all th
information needed to develop PL2303's driver. I think FTDI has a bette
product, the FT232BM, but PL2303 is much cheaper so I must choos
Prolific's product to reduce overall cost.

Site Timeline