Abstract: A method for detecting errors in a processing device is disclosed. A data source unit of a processing device transmits data and a qualifier synchronously with the data, the qualifier to indicate the data is uncorrectable. At least one intermediate functional unit in the processing device receives the data and the qualifier. The at least one intermediate functional unit detects the data is uncorrectable based on the qualifier. The at least one intermediate functional unit transmits, without using, the data and the qualifier synchronously with the data to a data consumer unit of the processing device. The data consumer unit receives the data and the qualifier. The data consumer unit detects the data is uncorrectable based on the qualifier. The data consumer unit maintains, without using the data and the qualifier.

Abstract: A method for detecting errors in a processing device is disclosed. A data source unit of a processing device transmits data and a qualifier synchronously with the data, the qualifier to indicate the data is uncorrectable. At least one intermediate functional unit in the processing device receives the data and the qualifier. The at least one intermediate functional unit detects the data is uncorrectable based on the qualifier. The at least one intermediate functional unit transmits, without using, the data and the qualifier synchronously with the data to a data consumer unit of the processing device. The data consumer unit receives the data and the qualifier. The data consumer unit detects the data is uncorrectable based on the qualifier. The data consumer unit maintains, without using the data and the qualifier.

Abstract: A modular multi-service telecommunication access device includes a controller card and card slots for six peripheral cards and a power supply. Any of several types of peripheral cards can be inserted into the six card slots. A card present/protocol scheme allows an inserted card to recognize its address and communicate same as well as its communication protocol to the controller card via a PCM highway. The controller card sends both signaling information and management information to the peripheral cards via another PCM highway. A unique communication protocol allows for both real time signaling information and non-real time management information to be sent on the same channel. A microprocessor on the controller card includes an algorithm for managing messages to the various peripheral cards in the various card slots. A unique tributary addressing scheme allows for a simplified address used by external users to be converted to a more detailed internal address.

Abstract: A circuit and method for generating write compensated write data signals in magnetic data recording. The circuitry is programmable to enable generation of write compensation meeting a variety of write compensation specifications. In particular, the circuitry can be programmed to generate extra write pulses, to adjust the pulse width and to adjust the pulse spacing within data cells. In an example embodiment, an input waveform drives a reset input on a state machine. An output waveform shape is stored as a pattern of bits in a register. The state of the state machine determines which register bits are selected by a multiplexer for output as a new write compensated write data signal.

Abstract: A method for reliably measuring preformatted servo patterns, on a magnetic tape, for positioning a magnetic head. The tape has constant frequency stripes marking servo pattern areas. The drive reading the preformatted tape has a read channel amplifier with automatic gain control (AGC). When a stripe is detected, AGC is enabled. Before leaving a stripe, AGC is placed on hold. The amplitudes of two servo bursts are then measured with a gain that has been calibrated by a signal from a stripe. During the time AGC is enabled, the amplifier peak output is limited to less than half the maximum amplifier peak output. The servo pattern signal amplitude is about twice the signal amplitude of a stripe, so that servo patterns are measured with almost the maximum signal-to-noise ratio. When a stripe is detected, a counter counts pulses resulting from the stripe signal, for a fixed time, to ensure that the stripe detection is valid.