Content originally posted in LPCWare by Cliff Bell on Mon Mar 14 14:11:53 MST 2011
I'm new to NXP micros but not to electronics.
If you believe the "good book" then I'm well over my alloted time!
I was designing circuits when bistable circuits used double triode valves, and OC71's were state of the art semiconductors!
I've had to learn, through the years, about both analogue and digital integrated circuits.
My fondest memory is converting a mechanical teletype machine to programme a memory chip for a SCAMP microprocessor!
The objective was to create a digitally programmed Flip-Flop! And it worked!
Later a Commodore Pet desktop computer speeded the process.
With a basic text editor to generate .asm files, programming was a doddle.
My problem now is that I have, over the intervening years, designed embeded firmware packages for a number of micros.
Each needed to pass FDA scrutiny for medical products.
They were all written in assembler and were very very time critical.
So much so that all critical instructions (and there are a lot!) always occur at the same time relative to others.
Timing needs to be a selection of an integral number of system clock cycles.
None can use interrupts.
The basic timing framework has migrated successfully through Intel, Microchip, Atmel and Hitachi processors.
All these versions were programmed in assembler.
My challenge is to port this software (firmware) to the LPC1343 and use some of the peripherals without upsetting this accurate timing structure. The bean counters think they will get more performance for their pennies!
I have Joseph Yiu's book, The Definitive Guide to the ARM Cortex-M3, and feel reasonably comfortable with its content.
However I'm overwhelmed by the number of windows on the LPCxpresso GUI.
Can I write a .asm (.s ???) programme in a simple text editor and drop it into one of the windows, where it will assemble into an executable for the evaluation board?
I guess setting up to debug such a simple approach may be a bit more complex, but if I can get the LED to flash on the eval board as directed by my own efforts, I guess I can dream up a simple debug relocatable add on.
Fortunately at my age, "time to market" is less important than thoroughly understanding what is going on!
Thanks
