Hewlett-packard Company

Jonathan Firooz

J Robert Sims, Iii

Michael J O'Brien

A method of automatically configuring an autoconfigurable computer peripheral device as a primary device or as a secondary device. There are four possible cases: (1) no other device present, (2) legacy primary device present, (3) legacy secondary device present and (4) second autoconfigurable device present. Host computer device configuration application software provides a signal or numerical data indicating a bit position within an identification number within each autoconfigurable device. If a device identification has a particular logical value at the bit position, the device responds to the signal from the computer. If the device identification has a different particular logical value at the bit position, the device determines whether another device is responding to the signal from the computer. If a first device determines that it should not respond, and a second device responds, the first device provisionally configures itself as a secondary device. If all bit positions are exhausted, and a device has not provisionally configured itself as a secondary device, then the device provisionally configures itself as a primary device. The host computer then sends a particular numerical value to the devices. Depending on the particular numerical value, each device configures itself to its provisional configuration, or to the opposite configuration from its provisional configuration, or unconfigures itself.

Autoconfigurable device that provisionally configures itself as the primary or secondary peripheral device depending on if another peripheral device is present

A firmware controlled device saves status and configuration information in a separate portion of memory that is not affected by a firmware update. In addition, information that may change during a firmware update, and may need to remain constant, is saved in the separate portion of memory that is not affected by a firmware update. In a first example embodiment, a reset process for the firmware controlled device is divided into two portions. In a first portion of the device reset process, the contents of the separate portion of memory are updated, either from firmware or by interaction with other devices. In a second portion of the device reset process, all other reset functions are performed. The first portion of the reset process is performed only during a power-on reset, or in response to an overall system reset. In particular, the first portion of the device reset process is not performed after a firmware update. In the second example embodiment, data that needs to remain constant are copied to the separate portion of memory as part of a firmware update process. Then, as part of a reset process, the device checks to see if a firmware update has occurred. If a firmware update has occurred, the data in the separate portion of memory are copied to the appropriate destinations, and the data in the separate portion of memory are cleared. As a result, for either example embodiment, the contents of the separate portion of memory are not disturbed during or after a firmware update, and a system reboot is not necessary after a device firmware update.

Method of updating firmware without affecting initialization information

A method of automatically configuring a computer peripheral device as a primary device or as a secondary device. There are four possible cases: (1) no other device present, (2) legacy primary device present, (3) legacy secondary device present and (4) second unconfigured device present. Each unconfigured device determines whether there are any legacy devices already installed and whether there is another unconfigured device installed without requiring any changes to the host operating system software. Unconfigured devices assert a signal after reset with a first timing that is dependent on an electronically readable identification on the device. For case (4), the first device to detect the signal becomes the secondary device. In case of a tie, unconfigured devices continue to assert the signal with a second timing that is dependent on the electronically readable identification on the device. A device that detects the signal being present at the end of the second timing configures itself as a secondary device. A device that does not detect the signal being present at the end of the second timing configures itself as a primary device.

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Loveland, CO, United States of America

Jonathan Firooz