Integrated semiconductor memory chip with presence detect data capability

Abstract

An integrated semiconductor memory chip includes hardwired presence detect data which can be accessed for transmission to a location external to the memory chip as well as logic allowing additional presence detect data to be programmed in the memory chip after fabrication of the memory chip. Storing the presence detect data on the memory chip rather than on a separate integrated circuit can help reduce the number of integrated chips required for a memory module, which may include multiple DRAM or other memory chips. Hardwiring at least some of the presence detect data during fabrication of the chip can reduce the number of programming errors as well as the number of mismatches that might otherwise occur if a separate presence detect data chip were used. On the other hand, the capability of programming presence detect data after fabrication of the memory chip provides additional flexibility, allowing the foregoing techniques to be used with a wide variety of memory chips and modules.