The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 15, 1995
Filed:
Sep. 16, 1993
Ray L Pickup, Brush Prairie, WA (US);
Mark R Thackray, Vancouver, WA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A printer controller employs a microprocessor together with an application-specific-integrated-circuit (ASIC) to manage the operation of the printer. Among its functions, the ASIC manages memory access for the microprocessor. Either fast- or slow-clock microprocessors may be installed in the controller, but the ASIC requires a slow clock. When a fast-clock microprocessor is installed, the ASIC must divide the clock frequency to provide its own (slow) clock. Likewise, the use of a fast-clock microprocessor requires the ASIC to insert memory-cycle WAIT times, whereas a slow-clock microprocessor needs no WAITs. In a preferred embodiment of the invention, provision is made, during initial power-on RESET, to inform the ASIC which clock speed is being used. This information is conveyed by the configuration of the WAIT interconnection between ASIC and microprocessor, thus eliminating the need for a dedicated ASIC pin for this purpose.