Signed Binary Multiplication (fixed point)?

Hello guys,

I am trying to do signed fixed point binary multiplication of two numbers:

-1 and 0.607252935.

My two numbers are both represented in the form Q2.14. I know that when you multiply these two numbers, the product will be of the form Q4.28, but I keep getting the wrong answer when the multiplier is negative...

Can you please show me how you would do -1*0.607252935 as described above?

Hope you can help!

Thanks!

For example you can strip the signs, multiply the numbers unsigned and then add the correct sign back.