L293D Motor driver IC

Hi guys, I've been using the motor driver module since few days and I'm well familiar with that module. But now I've to use more than 2 motors so for that reason I'm using L293D IC. In that Ic I can't found the PWM pin. can any one tell me how to vary speed using that IC?. As the speed can be varied using PWM pin in the Motor driver module? thanks in advance A.

You can PWM the enable inputs - thats the simplest, gives you fast decay mode.