Abstract: In some embodiments, a transmitter includes first encoding controlled frequency output circuitry to creates a magnitude encoded controlled frequency signal (CFS) and second encoding controlled frequency output circuitry to create a complementary a magnitude encoded controlled frequency signal (CCFS). Other embodiments are described and claimed.

Abstract: In some embodiments, a receiver includes a first conductor to carry a magnitude encoded controlled frequency signal (CFS) and a second conductor to carry a complementary magnitude encoded controlled frequency signal (CCFS). The receiver further includes circuitry to receive the CFS and CCFS from the first and second conductors and to decode them to produce an output signal. Other embodiments are described and claimed.

Abstract: An example embodiment of a computer system that includes a removable agent that can be removed or installed without powering down the system includes a fixed bus agent and the replaceable bus agent. The fixed bus agent and the replaceable bus agent are electrically coupled together by a presence detect signal, a synchronization signal, and a data bus. A deassertion of the presence detect signal indicates to the fixed bus agent that the removable bus agent has been disconnected and is no longer electrically coupled to the fixed bus agent. The fixed bus agent then tri-states its outputs and also prevents potentially invalid data from being delivered to the core circuitry of the fixed bus agent. An assertion of the presence detect signal indicates to the fixed bus agent that the replaceable bus agent is electrically connected to the fixed bus agent. In response to the assertion of the presence detect signal, the fixed bus agent and the replaceable bus agent enter reset periods.

Abstract: In some embodiments, a receiver includes a first conductor to carry a magnitude encoded controlled frequency signal (CFS) and a second conductor to carry a complementary magnitude encoded controlled frequency signal (CCFS). The receiver further includes circuitry to receive the CFS and CCFS from the first and second conductors and to decode them to produce an output signal. Other embodiments are described and claimed.

Abstract: In some embodiments, a transmitter includes first encoding controlled frequency output circuitry to creates a magnitude encoded controlled frequency signal (CFS) and second encoding controlled frequency output circuitry to create a complementary a magnitude encoded controlled frequency signal (CCFS). Other embodiments are described and claimed.

Abstract: A method and apparatus is presented where for transmitting data between two or more components. Data signals are sent in parallel with a clocking signal (e.g., on a bus) so that the data signal can be latched in relation to the clocking signal. For example, two clocking signals, out of phase from each other by 180 degrees, can be sent on bidirectional clocking signal lines and data signals can be sent on a data signal line, the component receiving the clocking and data signals can latch the data signals on each high-to-low transition of either of the two clocking signals. Using the method and apparatus of the present invention, skew problems seen with other bus systems can be reduced which leads to an increase in data transfer rates.

Abstract: An electronic circuit die is presented including a plurality of first and second input/output (I/O) pad buffer cells. The first I/O pad buffer cells include at least a latch for latching data signals received at a pad in the cell. Adjacent ones of these first I/O pad buffer cells are conductively coupled together using conductive trace pins. The second I/O pad buffer cells include a pad that receives clocking signal which are supplied to the latches of the first I/O pad buffer cells. Accordingly, data signals received at the pads of the die are latched in the pad as opposed to the core logic of the die. One benefit of providing the latching of data signals in the pad is that conductive traces between the latches and the core logic need not be precisely matched, thus reducing cost. Also, the first I/O pad buffer cells can be similarly constructed, thus reducing the complexity and cost of manufacture for the die.

Abstract: Methods and apparatus for easing design constraints with respect to placement of computer system components and subsystems requiring relative synchronicity is described. In one embodiment the apparatus includes a first and a second integrated circuit wherein each integrated circuit includes a first phase-locked loop (PLL) formed on an integrated circuit die. A reference clock signal pin is coupled to the first PLL by a path of electrical length L1 for propagating a reference clock signal to the first PLL. A first PLL driver is coupled to the first PLL. A first PLL feedback pin is coupled to the first PLL by a path of electrical length L2, wherein L1.apprxeq.L2. The first and second integrated circuits are cascade-coupled by coupling the first PLL driver of the first integrated circuit to the reference clock signal pin of the second integrated circuit using a propagation path of electrical length L3.

Abstract: Methods and apparatus for easing design constraints with respect to placement of computer system components and subsystems requiring relative synchronicity at different frequencies is described. In one embodiment the apparatus includes a first phase-locked loop (PLL) formed on an integrated circuit die. A reference clock signal pin is coupled to the first PLL by a path of electrical length L1 for propagating a reference clock signal to the first PLL. A first PLL feedback pin is coupled to the first PLL by a path of electrical length L2, wherein L1.apprxeq.L2. The apparatus includes a programmable counter coupled to the reference clock signal pin, the programmable counter providing a divided reference clock signal to the first PLL. In one embodiment, the method includes the step of providing a reference clock signal to a plurality of PLLs residing within a same integrated circuit. The outputs of at least some of the PLLs are coupled to corresponding output pins of the integrated circuit.

Abstract: An apparatus and a method for easing design constraints with respect to placement of computer system components and subsystems requiring relative synchronicity are described. In one embodiment, the apparatus includes a first phase-locked loop (PLL) coupled to a reference clock pin by a path of length L1 and a first PLL feedback pin by a path of length L2 such that L1.apprxeq.L2. In another embodiment, the apparatus includes a second PLL coupled to the reference clock pin by a path of length L3. The second PLL is coupled to an internal core of the integrated circuit by a path of length L4 such that L3.apprxeq.L4. In one embodiment, a computer system incorporating the apparatus includes a first propagation path of length L5 coupled to the first PLL output pin. The first PLL output pin is coupled to the first PLL feedback pin by a path of length L6 such that L5.apprxeq.L6.