US Patent 7475313 Unique pBIST features for advanced memory testing

This invention is new built-in self test instructions. A pointer register stores data identifying one bit of a data register. That bit determines whether the data of another data register is used in test in native form or in inverted form. Different built-in self test instructions update pointer including reset to the first bit, no change, increment to the next bit and decrement to the previous bit. For write instructions the selected normal or inverted data is written into memory. For read instructions the selected normal or inverted data is compared with data read from a memory.