Various techniques are provided to correct for hold time violations using input/output (I/O) block hardware of a programmable logic device (PLD) without requiring additional mapping, placement, or routing operations. In one example, a computer-implemented method includes receiving a design identifying operations to be performed by a PLD. The method also includes assigning components of the PLD to perform the operations. The method also includes routing a signal path among the components. The method also includes detecting a hold time violation for the signal path at an I/O block of the PLD. The method also includes selectively adjusting a variable delay cell of the I/O block to correct the hold time violation.