ASIC with selectable output drives

摘要

An ASIC (5) has four driver circuits (19a-19d), each with different output power. One of those driver circuits is selected from the content of register (13) on the ASIC, the register content being decoded by a decoder (15) on the ASIC to a signal which activates a single one of the drivers. The register is loaded from an external microprocessor (3) during each initialization of a printer (1) in which the ASIC (5) is a component. The ASIC is designed with the range of the powers of the drivers (19a-19d) bracketing the estimated needs of the load (11) to be attached to the ASIC (5). This permits the design of ASIC (5) to be completed only once, while the most suitable driver (19a-19d) for the final load (11) is determined subsequently and selected by the entry of data to activate that driver into the register (13) with each initialization of the printer. The ASIC (5) need not have nonvolatile memory and only a single set of ASIC masks and other design aspects need be completed.