hi .. . i have question iwant to lpc21xx get analog data and change it to digital after that show on lcd Character(2*16). i know code vision and avr but in arm and keil im beginner . please answer my question i should know that.
No real difference to use an ARM chip and Keil.
It's still mostly standard C.
So spend 30 minutes reading through the processor documentation for the ADC - that will tell you how to get your measurements.
Then look at a blinky program and check the processor documentation för GPIO. That will tell you how to play with the I/O pins of the processor - when you can play with the processor pins, then you can use basically identical code to interface with the display as you would on an AVR processor.
There is ample sample code available, and NXP has good documentation for the different processor features.