Hi I just started working on arm and I want to know Can we access or fetch a specific file( text,hex) from pendrive to arm controller to update controller firmware.
"I just started working on arm"
Maybe start here, then: www2.keil.com/.../learn
See also: http://www.keil.com/books/
Note that neither USB nor firmware update are beginner projects, though.
"Can we access or fetch a specific file( text,hex) from pendrive ..."
It has nothing specifically to do with ARM.
The USB functionality is provided by and proprietary to the particular chip manufacturer - so you will have to refer to the manufacturer's documentation for details of capabilities and restrictions.
But, yes, that would be a pretty standard thing to do with a USB Host - you will most probably find that the chip manufacturer provides (an) example(s) of doing exactly that.
Keil has middleware for doing that: www2.keil.com/.../middleware
Many 3rd-party middleware libraries are available.
"... to arm controller to update controller firmware"
Again, for the capabilities and restrictions of a particular chip to update its own firmware, you will have to refer to the manufacturer's documentation for that chip.
It is commonly supported - you will need a bootloader.
It is certainly possible, but requires some level of competence across a number of topic areas.
STMicro has a specific example for their STM32F4-Discovery board
Sir can you suggest a controller for this problem statement
Sir suggest that I have to learn for this
See the links I posted earlier.
I sounds like a school/college assignment - if so, seek support from your tutors / teachers / supervisors
What do you know already: - do you have any embedded 'C' programming experience? - do you have any basic electronics experience? - do you have any experience with, or understanding of, USB?
As noted above, STMicro has a specific example - so seek that out.
The Cortex-M is a very widely used architecture - there is plenty of material out there.
ST have a YouTube channel: www.youtube.com/.../UCjnmZw3h4XnpK3e5D2jvIGA including STM32 Online Training (OLT): www.youtube.com/.../playlists
ST's online learning: www.st.com/.../stm32-moocs.html
ST and their distributors frequently run real life training workshops/seminars - see what you can find locally.
They also do webinars: www.st.com/.../recorded-webinars.html
Thanks sir