摘要:
An ECC verification circuit including a first biasing circuit that is configured to output a predetermined logical signal. The verification circuit further includes a switch connected between the first biasing circuit and a first data bit line of a memory data bus of a computer system. The memory data bus includes a plurality of data bit lines and a plurality of check bit lines and the computer system includes error correction circuitry that is coupled to the memory data bus. The verification circuit is configured to activate the switch during a verification cycle of the computer system. In this manner, the predetermined logical signal is applied to the first data bit line during the verification cycle. The verification circuit is designed to apply a test state to the data bit lines and check bits lines of the memory data bus. The test state applied to the check bits line varies from the check bit state that would be generated by the ECC unit of the computer system upon receiving the test state that is applied to the data bit lines.
摘要:
A computer system includes a memory subsystem which has DIMM slots capable of receiving both DRAM and SDRAM memory module devices. A memory device detection methodology detects the presence of installed memory modules in the memory module slots, and signal levels on predetermined pins of the installed memory modules are processed to identify the specific type of memory module installed. The mode of an associated memory controller is set according to the type of module detected to be present, and the characteristics for the memory module are read.
摘要:
An apparatus and method for memory bus tuning are implemented. A plurality of drivers having a plurality of selectable drive levels are coupled to a memory bus. The memory bus is connected to a memory device which may have a variable amount of memory, which may be in the form of dual-in-line memory modules (DIMM). A drive level is selected in response to a determination of the amount of memory included in the memory device. A register operable for receiving a data value corresponding to the amount of memory is coupled to the drivers, the drive level being selected thereby.
摘要:
A multiple fan sensing circuit for use with a single fan sense input and method of operation thereof. The multiple fan sensing circuit includes a logic circuit, coupled to the fan sense input, that combines feedback signals from a first fan and a second fan. The first fan generates a tach signal indicative of the first fan operation and the second fan, e.g., a stuck rotor type fan, generates either an ON or OFF signal indicative of the second fan operation. In a related embodiment, the second fan generates a logic high signal in response to a failure in the second fan. In an advantageous embodiment, the logic circuit is a connector and a logic low level in the combined operational signal indicates a failed fan.
摘要:
A method and implementing system is provided which includes a switching device as part of a circuit board transmission line or trace serially connecting a plurality of device terminal sockets to a common node. When device terminals are left unconnected, corresponding segments of the connecting transmission line on the circuit board are disconnected to provide transmission line segments corresponding to the number of devices actually used. As a result, signal transition time for signals at the common node is optimized in accordance with the number of devices actually used.
摘要:
A bus termination impedance verification circuit. The verification circuit includes a sense circuit comprised of a sense input node and a sense output node. A sense node of the sense circuit is connected to a signal conductor of a bus to detect the termination impedance of the bus. The voltage of the sense output node is indicative of the termination impedance of the bus when the sense circuit input node is activated. The comparator circuit includes a comparator input node and a comparator output node. The comparator input node is connected to the sense circuit output node. The comparator circuit is configured such that the comparator output node is indicative of whether the voltage of the comparator input node is within a specified voltage range. The voltage of the signal conductor, as detected by the sense circuit, will be a function of the impedance of the termination circuits connected to the bus. An excess or shortage of termination circuits connected to the bus will result in a detected control signal voltage that is not within the specified limits.
摘要:
A connector on a printed circuit board of a computer system is reused to reduce a number of connectors utilized on a motherboard of a computer system. By recognizing that some signals are common between a programming application performed during a manufacturing process and a second application performed while the computer system is a normal customer operation, the connector may be used to provide data values during both the manufacturing process and normal customer operation. Stated another way, data signals used to drive programmed data during the manufacturing process may be re-used to provide serial data to an input/output device during normal customer operation.
摘要:
A method for improved Logic Built-In Self-Test (LBIST) includes providing a plurality of control signal sets, by an LBIST controller, to an LBIST domain comprising a plurality of LBIST satellite modules. Each of the plurality of LBIST satellite modules receives an individual one of the plurality of control signal sets. The LBIST controller interleaves the LBIST channel scan and LBIST sequence operations for each of the LBIST satellite modules, through the plurality of control signal sets.A test system includes a Logic Built-In Self-Test (LBIST) domain comprising a plurality of LBIST satellite modules. An LBIST controller couples to the LBIST domain and provides a plurality of control signal sets to the LBIST domain, wherein each of the plurality of LBIST satellite modules receives an individual one of the plurality of control signal sets. The LBIST controller interleaves LBIST channel scan operations for each of the LBIST satellite modules, through the plurality of control signal sets.
摘要:
A virtual electronic fuse (VEF) apparatus and methodology are disclosed that permit the state of an electronic fuse to change from an un-blown state to a blown state and then back to a virtual un-blown state. In one embodiment, the electronic fuse may change from the virtual un-blown state back again to a virtual blown state. The fuse apparatus includes multiple VEFs, each VEF exhibiting a respective address. The fuse apparatus also includes an address pool including multiple address pool locations. A fuse programmer stores an address of one of the VEFs in one or more address pool locations to indicate one or more state changes for a particular VEF. The fuse programmer may also store different VEF addresses in different address pool locations to indicate state changes for different VEFs.
摘要:
A method and implementing system are provided for determining and retaining an identification number relevant to an electronic system component and/or component configuration. In an exemplary embodiment, existing pull-up resistors within a computer system are connected in a manner to enable associated circuitry to determine a pre-assigned identification number for the computer system. The identification number is stored in an identification number register and accessible for providing the identification number in response to a requests from other devices within the system.