Patent ID: 8782326

Claim:
A memory device electrically connectable to a host circuit, wherein the host circuit is a controller of a printer, the memory device comprising: a nonvolatile memory cell array; and a memory control circuit which sends data to and receives data from the host circuit, and which carries out writing of data to and reading of data from the memory cell array in access units of N bits where N is an integer equal to 2 or greater, wherein the memory cell array includes: a rewritable area in which both writing of data and reading of data are permissible; and a read-only area in which writing of data is prohibited and reading of data is permissible, the rewritable area is configured so that the N bits constituting one access unit contain both actual data and an error detection code, the read-only area is divided between an actual data area in which the N bits constituting one access unit contain actual data, and an error detection code area in which the N bits constituting one access unit contain error detection codes; the memory control circuit reads data from the rewritable area; the memory control circuit reads data from the read only area subsequent to reading data from the rewritable area; the host circuit reads data from the read only area subsequent to detecting installation of the memory device; and the rewritable area stores information related to an amount of recording material consumed by the printer; and wherein in both the rewritable area and the read-only area, the N bits of each access unit comprises first data, and second data having a prescribed logical relationship to the first data.