in arm7tdmi, suppose instruction is being executed and at same time FIQ and IRQ both occur at same time.now according to priority FIQ will be handled then IRQ but my question is that how it will handled IRQ after return from FIQ
i means what will be process done at return of FIQ and how control will be transferred to IRQ handler after return statement of FIQ handler ?
example :
address => instruction
0x00000100 : MOV R0,R1
0x00000104 : MOV R0,R1
==> 0x00000108 : MOV R0,R1 ; suppose this is instruction being executed and FIQ and IRQ are raised at same time
0x00000110 : MOV R0,R1
0x00000114 : MOV R0,R1
0x00000118 : MOV R0,R1
thank you very much for solving my problem
and sorry for asking you same thing again and again but i wanted to be
quite sure.
actually i am firmware engineer and i have interest in ARM architecture so
i want to learn it literally and then i want to develop my own RTOS based
on ARM platform.so i need clear picture at ARM isa and ARM processor level
and how it works.
it is just that i am crazy about ARM.
again thank you,
nirav
Hi,
I am glad we got that clarified.
Also glad to hear of your interest in ARM. I would recommend, though, that you consider developing for a more modern processor tan ARM7TDMI. As far as we are concerned, that is very old technology these days and we would recommend using a more modern processor such as Cortex-M3 (for microcontrollers) or one of the Cortex-A series (for application processors).
Do let us know if there is anything else we can help with.
Best wishes
Chris
thank you sir,
so as you know i will have to start development form scratch with assembly and c langugae so can you suggest me any cortex-A sires processor development board with which i can get full software tool support and debugging and emulation support at very low level programming.
some known development boards are there but those are good for application programming on top of some kernel but while developing rots i need to do bare-metal coding and need good support of software and debugging and emulation
The Raspberry Pi Model B uses a quad core Cortex-A7 processor. Tools availability is excellent and bare-metal development is well supported and there is a lot of literature about this online.
Though I don't have a RasPi myself, I second chrisshore's suggestion. The Raspberry Pi is an excellent platform, which allows you to start from scratch or develop parts of your system under Linux and when you've finished enough components, you can put them together in a 'stand-alone' O/S.
In addition to the above, you might benefit from getting a WD PiDrive, which was developed specifically for the Raspberry Pi. -It's no coincidence that it's 314 GB either.
In case your development system is a PC, you could attach the PiDrive there, then move the drive to the Raspberry Pi for booting (or testing modules).