1. If i pull up the data lines by making DPULL to VCC +5V,will the status of data line change immediately?if not how will it affect the operation?
--When you connect the DPULL pin to the +5V pin, the lines will then be pulled high (+5V) through a 100 Kohm resistor. Therefore, when the lines are not being driven they will be pulled high.
2. After connecting DPULL to Vcc if i configure a port as a output port and if i write 8 bit data say 11001100 to port 2,the output will be same or the DPULL line will affect it in any way?
--Connecting the DPULL pin to +5V will only affect the data line when the line is not being driven. If you've configured a line/port for output and then output a certain pattern, the DPULL pin will not affect the output.
3. if i want to ch
eck the effect of CPULL & DPULL on data lines and control lines.What should i do?Which are the steps i should follow?
--To best test the effect of the CPULL & DPULL pins, I would test the voltage across the data lines and control lines on power-up or when the lines aren't being driven. If there is no connection to DPULL, then the lines will be pulled down through a resistor to ground (you'll read 0V). If you connect DPULL to +5V then the lines will be pulled high (you'll read 5V).
4. I have read in one note that you can pull up or down the lines without using jumpers.How it is possible?"
--You don't need to use jumpers, you just connect a wire from DPULL/CPULL to +5V or GND.
I hope this helps.
Regards,
Todd D.