Posts: 1
Registered: ‎08-09-2008
Accepted Solution


I used a F340+CP2201EB for simultaneous ethernet and UART communications. I got data from UART and relayed them to a distant server using TCP. The data were received from UART continously at the rate of 250 bytes/second and were then transmitted using TCP in packs of 240 bytes. At first, the data were sent by CP2201EB smoothly. However, intermittent data loss of 2-4 bytes per TCP pack was found during a continuous test of hours. I checked the memory in F340 and found the data loss originated from the intermittent loss from UART. The UART was driven by an interrupt! I made the UART interrupt high priority and the loss still happened. Is it possible that the UART interrupt is disabled during a TCP communication, and is there any method to solve the problem of data loss!
Posts: 6,327
Registered: ‎02-15-2004

Re: F340+CP2201EB

I heard that SiLabs TCP/IP stack disables interrupt for a while in somewhere on the stack routine. I've read it on this forum, but cannot find the post again. Ask it to SiLabs ( ).

a) Slower baudrate may solve the problem.

b) UART1 of 'F340 has three-deep FIFO for RX. It may work to hold the received data while disabled interrupt.

c) You may need to modify the stack routines to shorten the period of disabled interrupt.
SiLabs will open the source code of the TCP/IP stack under License Agreement. Contact to SiLabs.

Posts: 1
Registered: ‎04-11-2014

Re: F340+CP2201EB

Please tell me how to transfer UART data over Ethernet.

I am using F340+CP2201EB , i  am taking data from f850 uart . f850 UART (RX/TX) is connected to f340 UART (RX/TX) cross connection. This data taken from F850 to F340 should be tranmitted via Ethernet. Which inbuilt program to use. Or is there any other program to use????

Posts: 546
Registered: ‎10-12-2004

Re: F340+CP2201EB

Hi Sagar,


Ethernet is a tricky protocol to use, so I recommend finding a stack to implement that side of things for you.  CMX Micronet has one that supports the 'F34x, and you can contact them here for more information:


If you have another stack you want to use, we provide the low-level Ethernet routines for the 'F34x (attached) and 'F12x that you can use to add support to that stack for our devices.



Tabitha Parker
Senior Manager of MCU and Micrium Applications
Silicon Laboratories
Posts: 80
Registered: ‎01-06-2014

Re: F340+CP2201EB


slowing is not an option in your case (250B/s???). Look at the 34x example.

Is there some other processing in application? And yes, the long period 'interrupt disable ' can produce such effects!

This 240B takes >200us ENET INTR processing time, the 240B/s is >4ms/1B, therefore it's possible to have some sort of SYNCH issue.


regards, const