According to the datasheet, Vcp should be 12V relative to Vm, however on my board I'm getting Vcp=-.7V relative to Vm, when Vm=12V. What could account for this low voltage? I think I'm getting some shoot through since the upper transistors of the H bridge won't shut off correctly, and there's also some chatter in the motor that lessens when I apply a higher voltage to the Vcp pin.
--Greg