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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???
See: www.8052.com/.../160143
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.