Method and apparatus for limited reprogrammability of fuse options using one-time programmable elements

A circuit for selecting one of at least two operational modes for a semiconductor device, comprising:

• a plurality of one-time programmable devices each actuable from a first state to a second state;
• option circuitry, coupled to said plurality of one-time programmable devices to receive a plurality of logic signals reflecting the respective states of said plurality of programmable devices;
• wherein said option circuitry is responsive to said plurality of logic signals to assert a particular one of a plurality of distinct option signals, said particular one being determined based on the particular combination of respective states of said plurality of one-time programmable devices;
• wherein said semiconductor device is responsive to assertion of each of said plurality of distinct option signals to operate in a distinct one of said at least two operational modes;
• and
• wherein said option circuitry is responsive to at least two distinct combinations of respective states of said plurality of one-time programmable devices to assert the same option signal, such that said semiconductor device can be programmed to operate first in a first of said at least two operational modes, then in a second of said at least two operational modes, and then again in said first of said at least two operational modes.

A method for selecting one of at least two operational modes for a semiconductor device, comprising:

• coupling a plurality of one-time programmable devices, each actuable from a first state to a second state, to an option circuitry;
• receiving, by said option circuitry, a plurality of logic signals reflecting the respective states of said plurality of one-time programmable devices;
• generating a particular one of a plurality of distinct option signals, wherein said particular one being determined based on the particular combination of respective states of said plurality of programmable devices;
• operating said semiconductor device in a distinct one of said at least two operational modes in response to assertion of each of said plurality of distinct option signals;
• and
• generating the same option signal in response to at least two distinct combinations of respective states of said plurality of one-time programmable devices, such that said semiconductor device can be programmed to operate first in a first of said at least two operational modes, then in a second of said at least two operational modes, and then again in said first of said at least two operational modes.

A method for selecting one of at least two operational modes for a semiconductor device, one of said at least two operational modes being a default mode, comprising:

• coupling a first one-time programmable device and a second one-time programmable device to an option circuitry, wherein said first and second one-time programmable devices are actuable from a first state to a second state;
• actuating said first one-time programmable device to said second state while said second one-time programmable device is in said first state;
• generating a first option signal in response to said first one-time programmable device being actuated to said second state and said second one-time programmable device being in said first state;
• operating said semiconductor device in a first mode when said first option signal is generated, wherein said first mode is distinct from said default mode;
• actuating said first and second one-time programmable devices to said second state;
• generating a second option signal in response to said first and second one-time programmable devices being actuated to said second state;
• and
• operating said semiconductor device in said default mode when said second option signal is generated.