Abstract: A driver capable of launching signals into a transmission line and of terminating signals at a receiver end of the transmission line includes within the driver a circuit for controlling the output impedance and a circuit for controlling the output slew rate. Accordingly, a desired output impedance can be advantageously established and maintained over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a driver also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance. The driver includes a pull up circuit coupled to receive at least one of a plurality of control codes. The pull up circuit includes pull up output circuit and an impedance control buffer circuit, a parallel pull up circuit, the parallel pull up circuit and the pull up output circuit being controllable to adjust the impedance of the pull up circuit.

Abstract: A Scheme-1 Termination scheme maximizes system signaling rates by minimizing the signal settling-time when the distance from the middle node to the intersection of the transmission lines is much smaller than the sum of the distances from the end nodes to the intersection of the transmission lines. If the distance from the middle node to the intersection of the transmission lines is not much smaller than the sum of the distances from the end nodes to the intersection of the transmission lines, it has been discovered that a Scheme-2 Termination scheme minimizes the signal settling-time. Alternately, when a Scheme-3 Termination scheme is available, the Scheme-3 Termination scheme maximizes system signaling rates by minimizing the signal settling time when the third transmission line length is more than the second transmission line length divided by two. Otherwise a Scheme-1 Termination scheme minimizes the signal settling time.

Abstract: A driver capable of launching signals into a transmission line and of terminating signals at a receiver end of the transmission line includes within the driver a circuit for controlling the output impedance and a circuit for controlling the output slew rate. Accordingly, a desired output impedance can be advantageously established and maintained over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a driver also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance. The driver includes a pull up circuit coupled to receive at least one of a plurality of control codes. The pull up circuit includes pull up output circuit and an impedance control buffer circuit, a parallel pull up circuit, the parallel pull up circuit and the pull up output circuit being controllable to adjust the impedance of the pull up circuit.

Abstract: A driver capable of launching signals into a transmission line and of terminating signals at a receiver end of the transmission line includes within the driver a circuit for controlling the output impedance and a circuit for controlling the output slew rate. Accordingly, a desired output impedance can be advantageously established and maintained over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a driver also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance. The driver includes a pull up circuit coupled to receive at least one of a plurality of control codes. The pull up circuit includes pull up output circuit and an impedance control buffer circuit, a parallel pull up circuit, the parallel pull up circuit and the pull up output circuit being controllable to adjust the impedance of the pull up circuit.

Abstract: A receiver is provided which quickly and efficiently recognizes signals by including with the receiver a resolving circuit which is coupled to a signal generation circuit which provides a differential current. The resolving circuit is coupled to a latching circuit. The resolving circuit can operate with supply voltage levels as low as one threshold voltage. Also, the signal setup and hold times are inherently vary small due to the high intrinsic bandwidth of the receiver. Other advantages include reduced power consumption, high speed operation, good rejection of input noise and power supply noise, ability to resolve small (e.g., 1.0 mVolt) voltage differences, reduced capacitive loading, and the ability to function with a variety of types of drivers, including HSTL, DTL and PECL.

Abstract: A method may be provided which controls the output impedance of a driver which includes within the driver an impedance circuit and a slew rate control. Accordingly, a desired output slew rate and a desired output impedance can be advantageously established and maintained over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a method also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance.

Abstract: A driver may be provided which controls output impedance of a driver which includes within the driver an impedance circuit and slew rate control. Accordingly, a desired output slew rate and a desired output impedance can be advantageously established and maintained over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a driver also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance.

Abstract: An information handling system includes a plurality of transmission lines coupled together at one end and having a characteristic impedance, a driver circuit coupled to one of the transmission lines, a plurality of receiver circuits individually coupled to distinct ones of the transmission lines for resolving the signals, and on-chip terminators having a output impedance corresponding to the characteristic impedance and that can be coupled or decoupled from a node by on-chip circuitry. In this embodiment, the terminators are separate and distinct from driver circuitry. However, when a node is in a receive configuration, its corresponding termination resistor is tied to the transmission line at that node, and its corresponding driver circuit presents a high impedance output to the node.

Abstract: An information handling system includes a plurality of transmission lines coupled together at one end through resistance elements having a particular resistance, a driver circuit coupled to one of the transmission lines, a plurality of receiver circuits individually coupled to distinct ones of the transmission lines for resolving the signals, and on-chip termination resistors having a resistance corresponding to the characteristic impedance and that can be coupled or decoupled from the output node by on-chip circuitry. In this embodiment, the termination resistors are separate and distinct from driver circuitry. However, when the node is in a receive configuration, its corresponding termination resistor is tied to the transmission line at that node, and its corresponding driver circuit presents a high impedance output to that node.

Abstract: A method of controlling impedance of a driver capable of launching signals at a driving end of a transmission line and capable of terminating signals at the receiver end of the transmission line controls the impedance of the driver across process, voltage, and temperature (PVT) variations by selectively enabling and disabling at least one of a plurality of output elements according to an impedance control code. The impedance control code compensates for variations in output impedance due to PVT variations.

Abstract: A dynamic termination logic driver, one that is capable of launching signals at a driving end of a transmission line and is capable of terminating signals at a receiver end of the transmission line, controls output impedance and includes within the driver an impedance circuit and slew rate control. Accordingly, a desired output impedance can be advantageously established and maintained over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a driver also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance. The driver includes a pull up circuit coupled to receive at least one of a plurality of control codes and the driver also includes a pull down circuit coupled to receive at least one of the plurality of control codes.

Abstract: A dynamic termination logic driver, the driver capable of launching signals at a driving end of a transmission line and terminating signals at a receiver end of the transmission line, controls slew rate over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a driver also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance. The driver includes a pull up circuit having an impedance, the pull up circuit including a pull up output circuit and a buffer circuit, the pull up output circuit including a parallel pull up circuit, a pull up output control circuit, and a pull up slew rate control circuit, wherein the parallel pull up circuit and the pull up output control circuit are coupled in parallel.

Abstract: A receiver is provided which quickly and efficiently recognizes signals by including with the receiver a resolving circuit which is coupled to a signal generation circuit which provides a differential current. The resolving circuit is coupled to a latching circuit. The resolving circuit can operate with supply voltage levels as low as one threshold voltage. Also, the signal setup and hold times are inherently very small due to the high intrinsic bandwidth of the receiver. Other advantages include reduced power consumption, high speed operation, good rejection of input noise and power supply noise, ability to resolve small (e.g., 1.0 m Volt) voltage differences, reduced capacitive loading, and the ability to function with a variety of types of drivers, including HSTL, DTL and PECL.

Abstract: A driver may be provided which controls the output slew rate a driver which includes within the driver a slew rate control circuit. Accordingly, a desired output slew rate can be advantageously established and maintained over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a driver also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance.

Abstract: A method for a driver may be provided which controls the output slew rate of a driver which includes within the driver an impedance control and a slew rate circuit. Accordingly, a desired output slew rate and a desired output impedance can be advantageously established and maintained over a wide range of variations in operating conditions, manufacturing processes and output voltage levels. Such a method also advantageously limits any crowbar current, thereby reducing the overall power consumption of the driver with little, if any, degradation of driver performance.

Abstract: An information handling system includes a plurality of transmission lines coupled together at one end and having a characteristic impedance, a driver circuit coupled to one of the transmission lines, and at least one receiver circuit coupled to the transmission lines. At least one driver circuit includes pull-up and pull-down circuits each having output resistances. The parallel combination of the pull-up and pull-down resistances matches the characteristic impedance of the transmission line. When the driver is used to terminate the transmission line, the pull-up and pull down circuits are enabled at approximately the same time, thus terminating the line. On-chip terminators may alternatively be used for termination, the terminators either including pull-up and pull-down circuits substantially similar to those described for the drivers, or may include a single resistance tied to a voltage other than an upper or lower rail.

Abstract: An information handling system is disclosed herein. The system includes at least one system transmission line having a characteristic impedance and a plurality of clusters, each cluster being coupled to each other cluster through at least one of the system transmission lines. Each cluster comprises at least one cluster transmission line each having a characteristic impedance equal to the characteristic impedance of the system transmission lines, and is coupled to a the system transmission line and a circuit chosen from the following: a driver, an on-chip terminator, an off-chip terminator; each driver having a pull-up circuit having an output resistance matching the characteristic impedance of the cluster transmission lines.

Abstract: A method for terminating signals in an information handling system comprises includes providing a plurality of resistance elements, providing at least three transmission lines each having a characteristic impedance, each of the transmission lines having a first end, each of the first ends being coupled together through said resistance elements, and a second end, and providing a plurality of drivers equaling the number of transmission lines in the plurality of transmission lines, each driver coupled to a second end of a different one of the transmission lines, each driver comprising a pull-down circuit having a pull-down resistance matched to the characteristic impedance of one of the lines, and a pull-up circuit having a pull-up resistance corresponding to the number of second ends.

Abstract: A method for operating an information handling system comprises includes providing at least three transmission lines each having a characteristic impedance, each of the transmission lines having a first end, each of the first ends being commonly connected to each other first end, and a second end, and providing a plurality of drivers equaling the number of transmission lines in the plurality of transmission lines, each driver coupled to a second end of a different one of the transmission lines, each driver comprising a pull-down circuit having a pull-down resistance matched to the characteristic impedance of one of the lines, and a pull-up circuit having a pull-up resistance corresponding to the number of second ends. The method further includes providing at least one receiver circuit coupled to a second end of one of the transmission lines, designating one of the drivers as an active driver, and designating each driver in the plurality of drivers other than the active driver as a terminating driver.

Abstract: A receiver is provided which quickly and efficiently recognizes signals by including with the receiver a resolving circuit which is coupled to a node control circuit which determines the signals to be recognized. The resolving circuit can operate with supply voltage levels as low as one threshold voltage. Also, the signal hold time can be made very small depending on the sizing of certain transistors. Other advantages include reduced power consumption, high speed operation, good rejection of input noise and power supply noise, ability to resolve small (e.g., 1.0 mVolt) voltage differences, and the ability to function with a variety of types of drivers, including HSTL, DTL and PECL.