Physically unclonable function with precharge through bit lines

A method for performing a read operation of a bit cell in a physically unclonable function (PUF), the read operation comprising:

• precharging a latch in the bit cell with the latch decoupled from a supply voltage node, the precharging including coupling a first output of a digital to analog converter (DAC) circuit to a first internal node in a latch of the bit cell through a first bit line and a first transmission gate and coupling a second output of the DAC circuit to a second internal node in the latch through a second bit line and a second transmission gate;
• disconnecting the first and second bit lines from the first and second internal nodes after allowing for a settling time for the precharge of the bit cell;
• precharging the first bit line and the second bit line to a predetermined voltage level after the settling time with the first and second bit lines disconnected from the first and second internal nodes;
• after precharging the first and second bit lines, coupling the latch to the supply voltage node to cause the bit cell to regenerate;
• and
• reading a value of the latch using at least one of the first and second bit lines.

A method, comprising:

• precharging a latch in a bit cell of a physically unclonable function (PUF) using a differential voltage applied to first and second bit lines with the latch decoupled from a supply voltage node;
• after precharging the latch, precharging the first and second bit lines while the first and second bit lines are disconnected from the latch;
• causing the latch to regenerate by coupling the latch to the supply voltage node;
• and
• reading a value of the latch using at least one of the first and second bit lines.