Semiconductor Device Having Features to Prevent Reverse Engineering

摘要

A ROM circuit includes a first N channel transistor having an output and having device geometry and device characteristics adapted to bias the output at a predetermined level when a P channel circuit is connected to the first N channel transistor; a pass transistor connected between the output and a data bus, the pass transistor connected to a word line, the word line adapted to turn ON the pass transistor when the word line is asserted; and the P channel circuit connected to the data bus and adapted to provide leakage current to charge a gate in the first N channel transistor when pass transistor is turned ON.

主权项

1. A ROM circuit comprising:
a first transistor having an output and having device geometry and device characteristics adapted to bias the output at a predetermined level indicating a binary 1 or a binary 0 when a circuit is connected to the first transistor through a pass transistor; the pass transistor connected between the output and a data bus, the pass transistor connected to a word line, the word line adapted to turn ON the pass transistor when the word line is asserted; and the circuit connected to the data bus and adapted to provide leakage current to charge a gate in the first transistor when pass transistor is turned ON.