Patent ID: 7407261

Claim:
An image processing apparatus for a pagewidth inkjet printer that includes an array of printhead chips that span a print area, the apparatus comprising an elongate support structure for supporting the array of printhead chips; a plurality of printed circuit boards mounted end-to-end on the support structure, each printed circuit board comprising a memory device; an application specific integrated circuit (ASIC) that is connected to the memory device, the ASIC being configured to accept data to be written to the memory device and to write data from the memory device to at least one respective printhead chip; a serial bus that is connected to the ASIC to write data to the ASIC; and a microcontroller that is connected to the ASIC so that the microcontroller can write data to the memory device, via the ASIC; and a plurality of connectors, each connector being interposed between a respective ASIC and said at least one respective printhead chip to connect said respective ASIC to said at least one respective printhead chip, in which each ASIC comprises: a data bus; a high-speed interface that is connected between the data bus and the microcontroller to permit the microcontroller to write to the data bus; a memory device interface that is connected between the data bus and the memory device to permit data to be written to and from the memory device; a printhead interface that is connected between the data bus and printhead chips to permit data to be written to the printhead chips; and a controller that is connected between the serial bus and the data bus to control operation of the ASIC.