Browse Prior Art Database

Peripheral Device Emulator

IP.com Disclosure Number: IPCOM000014182D
Original Publication Date: 2000-Dec-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 2 page(s) / 77K

Publishing Venue

IBM

Abstract

Disclosed is a circuit that emulates the behavior of peripheral devices such as a keyboard, pointing device, etc.. by responding to the peripheral device controller of a system motherboard with the responses that are expected during POST (Power On Self Test) and the boot-up of an Operating System.

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Peripheral Device Emulator

Disclosed is a circuit that emulates the behavior of peripheral devices such as a keyboard, pointing device, etc.. by responding to the peripheral device controller of a system motherboard with the responses that are expected during POST (Power On Self Test) and the boot-up of an Operating System.

In a peripheral switch environment, such as that dealing with Keyboard / Video / Mouse devices, the peripherals are connected to only one system at a time. When a rack filled with systems is powered up, all the systems will concurrently perform testing for the presence of the devices during the execution of POST, then again when the Operating System boots up. If the system unit fails to receive the proper response from a peripheral device, an error is declared and the device is deemed to be malfunctioning and/or declared as "not connected". By implementing a circuit that responds in the manner that the peripheral device would (if it were connected) the advantages that are derived are the avoidance of unnecessary error messages, as well as the improvement of test coverage. The later is specially crucial when employing a serial, daisy-chain connection scheme in a dense environment of rack mounted systems.

Functionally, if the switch control circuit has enabled the connection of the peripheral device controller to the peripheral device, the device emulator is disabled. If, however, the switch control unit has disabled the connection of the periph...