Field programmable antifuse device and programming method therefor

In a programmable device, a method for reducing a resistance between a first portion of an antifuse to be programmed and a conductor carrying a first programming voltage, comprising the steps of:

• establishing a first conductive programming branch from a source of said first programming voltage to said first conductive programming branch being a first programming voltage driver;
• and
• establishing a second conductive programming branch from a source of said first programming voltage to a location on said first conductive programming branch, said location being spaced from said first portion of said antifuse to be programmed, said source of said first programming voltage of said second conductive programming branch being a second programming voltage driver.

In a programmable device, a method for reducing a resistance between a first portion of an antifuse to be programmed and a conductor carrying a first programming voltage, comprising the steps of:

• establishing a first conductive programming branch from a source of said first programming voltage to said first portion of said antifuse to be programmed;
• and
• establishing a second conductive programming branch from a source of said first programming voltage to a location on said first conductive programming branch, said location being spaced from said first portion of said antifuse to be programmed, wherein said antifuse to be programmed is a pass antifuse.

In a programmable device, a method for reducing a resistance between a first portion of an antifuse to be programmed and a conductor carrying a first programming voltage, comprising the steps of:

• establishing a first conductive programming branch from a source of said first programming voltage to said first portion of said antifuse to be programmed, at least a portion of said first conductive programming branch being disposed on a first circuit layer of said programmable device;
• and
• establishing a second conductive programming branch from a source of said first programming voltage to a location on said first conductive programming branch, said location being spaced from said first portion of said antifuse to be programmed, at least a portion of said second conductive programming branch being disposed on a second circuit layer of said programmable device.

A method for at least partially programming a first antifuse, comprising the steps of:

• establishing a first conductive branch from a first source of a first voltage to a first antifuse;
• and
• establishing a second conductive branch from a second source of said first voltage to a second antifuse, said second antifuse electrically contacting said first conductive branch, said second antifuse being a cross antifuse which is already at least partially programmed.

A method of realizing a user-specific circuit in a field programmable gate array chip, said user-specific circuit receiving a plurality of off-chip input electrical signals during normal operation and outputting a plurality of off-chip output electrical signals based on said off-chip input electrical signals during normal operation, said user-specific circuit comprising a plurality of digital logic components and a plurality of interconnection nets, each of said nets of said userspecific circuit being switchable during normal operation to determine said off-chip output electrical signals based on said off-chip input electrical signals, comprising the step of:

• programming a programming-access antifuse during a programming operation and before said normal operation, said programming of said programmingaccess antifuse establishing a programming branch extending from a programming driver to one of said plurality of nets through said programming-access antifuse during antifuse programming, no output terminal of any of said plurality of digital logic components of said user-specific circuit being electrically connected during normal operation to said one net through said programming-access antifuse.

A method of connecting a programming branch to a net of a user-specific circuit realized in a field programmable device, comprising the step of:

• programming a programming-access antifuse so that said programming branch is electrically connected to said net via said programming-access antifuse during antifuse programming.

In a programmable device comprising:

• a first conductive programming branch from a source of a first programming voltage to a first portion of an antifuse to be programmed;
• and
• a second conductive programming branch from a source of said first programming voltage to a location on said first conductive programming branch, said location being spaced from said first portion of said antifuse to be programmed, said second conductive programming branch being connected to said first conductive programming branch via a programming-access antifuse, said programming-access antifuse being spaced from said first portion of said antifuse to be programmed.

In a programmable device, a method for reducing a resistance from an antifuse to be programmed to a first programming voltage, comprising the steps of:

• establishing a first conductive programming branch from a first source of said first programming voltage to said antifuse;
• and
• establishing a second conductive programming branch from a second source of said first programming voltage to said first conductive programming branch, said second conductive programming branch not contacting said antifuse to be programmed, said second conductive programming branch not contacting said first source of said first programmed voltage.