Baud rate

historical

Hi Holger,

Well I looked into the code and figured ATMEL MCU used here takes Fi/Di as an input parameter for setting it’s UART. My question how do you figure the phone clock speed and baud rate?

I know that Baud Rate = Phone clock speed/(Fi/Di). So I need to know these parameters to sniff communication.

My Goal is to sniff the entire process of phone communication with SIM and store in a File. For that I need to know the phone’s clock speed and Baud rate of UART at different times.

Thanks,
Vishal
> On Jul 14, 2017, at 10:23 AM, Holger Freyther <holger at freyther.de> wrote:
> 
> 
>> On 14. Jul 2017, at 19:13, Vishal Vaidhyanathan <Vishal.Vaidhyanathan at privoro.com> wrote:
>> 
>> Hi,
> 
> Hi!
> 
> 
>> Sorry about that. Didn’t realize I was taking it private. I’ve a couple more questions. If the ATR comes back at 9600, doesn’t it stay the same until we send PPS?
> 
> Right.
> 
>> So I went through that link, according to that, after ATR, we use the Fi and Di values to calculate UART Baud rate and send commands in that rate? But I want to know what baud rate the phone uses? Does it change using PPS? Wireshark doesn’t show any PPS after ATR. Does that mean the phone read the ATR and adjusted the clock accordingly? Basically I’m trying to sniff the entire phone communication to SIM in a file and I need the correct Baud rate to do that?
> 
> You are right. If you look at process_byte it will not forward PTS related bytes (goto out_silent). At least in the debug output of the SIMtrace you should be able to see fi/di changes.
> 
> holger
> 

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