Pull-Up Resistor questions about value, rise time and fall time

How to calculate the correct pull-up resistor value?
how does my pull-up resistor affect the rise time of the signal?
If i add a pull-up will there be variation in rise time and fall time and do i need to compensate it?

calculate pull up resistor

when the pull-up resistance is very small the power dissipation increases and when it is very high it loads down the output because the output impedance and the pull-up form a voltage divider and you can guess what the output would be....
if there is capacitance in the pull-up resistor or the output impedance or the load then the rise time and fall time would surely be affected by the pull-up resistor....

how to calculate pull up resistor

pull up resistor is used to pull the output voltage level to suitable value.
Its value should not be too low neither there will be lot of current flow through transistor and total power dissipation will increase.
Its high value will also restrict the net output current.
Its value along with connected or calculated capacitance increases the time constant and hence the total rise time or fall time.

pull-up resistor

Jebakumar Samuel,
If you know the value of the capacitive load on the output, you can calculate the maximum allowable resistance of pullup resistor by solving the equation.
Vo = Vin(1-exp(-t/RC)) for R, where
Vin is the minimum steady-state "1" output.
t is the maximum allowable rise time fro the output to reach Vo.
Vo is the minimum acceptable "1" level output.
Then
R = t/{C ln[Vin/(Vin-Vo)]}.
"ln" means "natural logarithm".
After calculating R, you must determine whether the driving device is capable of sinking the current that will flow into the output when the output is in the "0" state. If it is not, then you can not meet your design requirement. You must use a larger value of pullup resistor, and live with the increased rise time of the output.
Regards,
Kral