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After connecting external keypad and display to ARM7 MCB2140,is there any software application to be loaded or executed to make it operate???
Have you read the datasheet for the processor, in regards to the possibility of using built-in pull-up or pull-down in the processor? Note that internal pull-up/pull-down is normally quite weak and is good to hold PCB-internal signals at a known state while the processor boots, but signals for a keyboard or anything that leaves the PCB should be driven a bit harder, to give better electrical protection from ESD or external interference.