We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
Hi All, I am not an expert on ARM yet but an average guy for uC.
I am trying to get hands on with LPC2148 and plan to use it in next project.
One wonderful thing that I came across (I come form a background where we use 8051/mega16 uC) is USB IAP. So without any UART/Serial cable, I can flash program just by using USB cable.
Did some changes like 1. generating bin file (using fromelf --bin ....) and 2. changing IROM1 from 0x0 to 0x2000
to make program work with IAP.
I tasted some program and those worked very well.
But the issue is arising when I try to use Timer0 interrupt. I see controller getting stuck somewhere just after 1st int.
I checked with "Use Memory Layout with Target Dialog" selected and de-selected both. Nothing worked.
This has something to do with vector table but I am not able to make out what?
Any help on this would be appreciated.
Remember, I just made 3 above mentioned changes after creating new project. If there is anything else, please let me know.
John, A really strange thing is going on. After the Blinky worked well. I moved back to my earlier project and flash it. It just worked. I'm not sure how.
Even after spending some good, I couldn't figure out the issue.
So I decided to start a new project in keil and just copied the C file from the earlier version (Remember, this file was never touched in the whole process).
I made sure that Startup.s is original only (original of Keil, without RAM_INTVEC).
The only changes I made was to change IROM1 from 0x0 to 0x2000 and added Run Cmd to generate .bin.
NO ADDITION OF REMAP, RAM_MODE or RAM_INTVEC.
And, it worked.
Now, I am totally confused about what is going on.
Just to be careful about data in RAM, I re-plugged the power supply as well. Still it worked.
Did that Blinky made some changes?
I am planning to order one more of the same board. So will check this issue on that also. Till then, do you have some experiments which I should be trying on this board?
It is possible.
=== Flash === Bootloader Vector -> Both Bootloader and Application use this Vector Bootloader PROGRAM Bootloader PROGRAM Bootloader PROGRAM Bootloader PROGRAM Bootloader PROGRAM Bootloader ISR PROGRAM -> Both Bootloader and Application use this ISR ============= Application PROGRAM Application PROGRAM Application PROGRAM Application PROGRAM Application PROGRAM Application PROGRAM
One of the bootloaders you have tried, provided a usable ISR PROGRAM. If you did not erase this usable ISR PROGRAM, every Applications work fine.
LPC2148 seems quite old. LPC23xx/LPC24xx seem a little old. It is now LPC17xx. (LPC13xx?)
I think you are right.
So, in short, If 1. I get a new board (or completely erase the flash) 2. Program the USB Bootloader 3. Copy the newly working binary (not the Blinky)
it will not work immediately. I will need to run blinky once to make it running :)
LPC2148 may be old. But til now I was using AVR (8-bit) controllers. So I planned to move a level up so that next projects can be better.
And, to get familier with the uC, I got this Development board at very good rate. "">www.nex-robotics.com/.../arm7-lpc2148-development-board.html"
This will ramp up the development time.
I surely have a look at LPC17xx/13xx. But now as I have started with this, I plan to understand it properly. So the jump to 17/13xx would be easier.
BTW, thanks for suggestion.
Exception Vectors -> ARM design Vectored Interrupt Controller -> NXP design One of the Exception Vectors is linked to Vectored Interrupt Controller.
LPC21xx / LPC23xx -> ARM7 -> VIC LPC17xx (LPC13xx?) -> ARM Cortex-M -> NVIC
ARM7 is very different from Cortex-M; and due to the foundry process etc, Cortex-M might be cheaper than ARM7. But of course, different projects have different considerations, LPC2148 might still be the best choice for your projects. (When will NXP terminate LPC21xx?)