which software can help me to capture spi and i2c signal i need to present and explain the singal to my lecturer but sadly the oscilloscope in my lab is not competent enough. Can anybody suggest me a easy and powerful simulation software?

 

Sure. Set the device up to do repetitive transfers.
Trigger the trace on the leading edge of chip select(SPI) or SCL(I2C)
Set the sweep length to 1.5 times the length of the transaction.

 

I always found it most helpful to use that free spare pin on my device as a flag to indicate the start of a comm transfer. Even a 2 channel scope can then monitor the full clock and data signals if that flag is directed to the ext trigger input. You do need 3 probes.

If you crack open most any data sheet for a SPI or I2C device they will have a drawing of the required or expected signals. You can use most any drawing program to make a picture of what yo see in the lab.

There of course is always a pencil and paper. Most useful for any arbitrary shape.