1. Don't forget to add the start and stop bits when working out the data throughput (so with one stop bit, each data byte requires 10 bits of serial).
2. While a single byte will be sent at the baud rate, there is nothing to say the next one will follow immediately. Are you using handshaking or flow control?
thanks. no, i am not using hand shake or flow control. simply STM32F4 transmitting the DATA and PC is receiving it. there is no problem on STM32 side, AS if i would communicate between 2 controllers it will be done exactly on speed i calculated... but with PC it slows down. in matlab same result.
i have no loss of bit or byte. i think , there is some thing with PC buffer ...!!!
As per my knowledge most of the UART driver have some inherent delay routines....I mean to say you will get single byte with the baud rate that you specified but what happens when you are getting the byte there will be atleast one instruction delay....Also in case of puts function in UART driver there will be some delay in your routine....It is better to put your code for more insight on this....