Robust bit scheme for a memory of a replaceable printer component

A printing system comprising:

• a printhead for selectively depositing ink drops on print media;
• an ink supply for storing ink to be provided to the printhead;
• a memory device for storing a first parity bit and a first data item, the first parity bit associated with the first data item;
• and
• a processor coupled to the memory device by a plurality of electrically conductive lines, the processor responsive to output of the memory device, the processor configured to read the first parity bit, the processor configured to perform an electrical test of at least one of the electrically conductive lines, the processor configured to identify an error in the first data item based on the first parity bit and the electrical test.

A cartridge for a printing system having a controller, comprising:

• a printhead assembly having at least one printhead for selectively depositing ink drops on print media;
• an ink supply for storing ink to be provided to the printhead;
• and
• an information storage device storing a first parity bit and a first data item, the first parity bit associated with the first data item, the first parity bit for use by the controller in conjunction with an electrical test of electrically conductive lines coupled to the information storage device to identify an error in the first data item.

A replaceable printer component having an integral memory for use in a printing system, the component comprising:

• a semiconductor die;
• and
• a plurality of circuits formed on the semiconductor die, each circuit associated with and indicating the state of a bit in the memory;
• the memory storing a plurality of functional bits that must match values expected by the printing system for proper operation of the printing system, the memory storing a plurality of informational bits that are not critical to proper operation of the printing system, a large percentage of the circuits associated with the functional bits positioned substantially near a center of the semiconductor die, and wherein a large percentage of the circuits associated with the informational bits are positioned substantially outside of the center of the semiconductor die.

A method of storing information in a replaceable printer component having an integral memory, the replaceable printer component for use in a printing system, the method comprising:

• providing a semiconductor die with a plurality of circuits formed on the semiconductor die, each circuit associated with and indicating the state of a bit in the memory;
• identifying functional bit fields related to the replaceable printer component that must match values expected by the printing system for proper operation of the printing system;
• identifying informational bit fields related to the replaceable printer component that are not critical to the proper operation of the printing system;
• storing a large percentage of the functional bit fields in the semiconductor die using circuits that are positioned substantially near a center of the semiconductor die;
• and
• storing a large percentage of the informational bit fields in the semiconductor die using circuits that are positioned substantially outside of the center of the semiconductor die.