Hysteresis comparator with Dsp Builder

Hi!

I would like to model an hysteresis comparator with Dsp builder. It should first of all compare an input signed fractional signal with two signed fractional limits. When the signal is greater than the upper limit, we should have '1' at output T1 and '0' at T2; when it becomes smaller than the lower limit, the outputs should be '1' for T2 and '0' for T1. An finally, when the input signal is inside the hysteresis band, the outputs will memorize the previous states.

Please I've got trouble doing this. So I really need help.

Thanks in advance!