Externally clocked electrical fuse programming with asynchronous fuse selection

A DRAM comprising:

• a plurality of fuses;
• a plurality of fuse latch circuits for holding fuse programming data;
• a fuse pointer circuit for selecting fuses, the fuse pointer circuit configured to asynchronously advance past fuses that are not to be programmed to select fuses that are to be programmed, as indicated by the fuse programming data;
• and
• a blow circuit configured to apply a blow voltage to a fuse selected by the fuse pointer circuit if the fuse programming data indicates the selected fuse is to be blown, wherein the application of the blow voltage to the fuse is synchronized with a blow clock signal.

A method for sequentially programming a plurality of fuses, comprising:

• loading a plurality of fuse latch circuits with fuse programming data;
• initializing a fuse pointer to select a first fuse;
• providing a fuse blowing clock signal;
• advancing the fuse pointer to select a second fuse to be blown, as indicated by the fuse programming data, wherein the advancing is not synchronized with the fuse blowing clock signal;
• and
• blowing the second fuse, wherein the blowing is synchronized with the fuse blowing clock signal.

A method for sequentially programming a plurality of fuses, comprising:

• loading a plurality of fuse latch circuits with fuse programming data, wherein each fuse latch circuit holds a bit of fuse programming data to indicate whether an associated one of the fuses is to be blown;
• initializing a fuse pointer to select a first one of the fuses;
• generating a fuse blow clock signal, a fuse latch reset clock signal, and a pointer advance clock signal from an external clock signal;
• asynchronously advancing the fuse pointer during a pointer advance mode defined by the pointer advance clock signal until a second fuse to be blown, as indicated by the bit of fuse programming data held in the fuse latch circuit associated with the second fuse, is selected;
• blowing the second fuse, wherein the blowing is synchronized with the fuse blow clock signal;
• and
• changing the bit of fuse programming data in the fuse latch circuit associated with the second fuse during a fuse latch reset mode defined by the fuse latch reset clock signal.