摘要:
The hot socket detect circuit of the present invention includes a well bias circuit and three hot socket detect blocks. If the output of any of the three hot socket detect blocks is a digital high signal then the output of the hot socket detect circuit is a digital high signal. The digital high signal indicates that a hot socket condition exists.
摘要:
An AC current booster for high speed, high frequency applications having a single-ended output embodiment and a differential output embodiment. The embodiments of the present invention allow bifurcated control of the AC switching rate and the DC state of a given output signal, in order to achieve faster rising and falling edge rates without an undesirable increase in output voltage swing.
摘要:
A technique to provide higher system performance by increasing amount of data that may be transferred in parallel is to increase the number of external pins available for the input and output of user data (user I/O). A technique is to allow a pin to be used for multiple purposes, a dedicated operation during a first mode and for user I/O during other modes. A pin (515) may be used to perform a handshaking function during a configuration mode and user I/O during a normal or user mode. The technique may be used during the cascaded configuration of programmable integrated circuits, and in conjunction with in-system programming.
摘要:
The hot socket detect circuit of the present invention includes a well bias circuit and three hot socket detect blocks. If the output of any of the three hot socket detect blocks is a digital high signal then the output of the hot socket detect circuit is a digital high signal. The digital high signal indicates that a hot socket condition exists.
摘要:
Techniques for adjusting the boundary between bytes of data in a serial-to-parallel converter are provided. Bits of serial data are shifted into a first register. Data bytes are then shifted out of the first register along parallel signal lines into a second register. The timing of the parallel load of data from the first register to the second register determines the parallel data byte boundary. The boundary between the parallel data bytes can be shifted using a load enable signal. The phase of the load enable signal can be changed to shift the boundary between data bytes by one or more bits. The parallel data can then be loaded from the second register into a third register. The data output signal of the third register is synchronized to a core clock signal to ensure enough set up and hold time for signals output by the third register.
摘要:
Techniques for adjusting the boundary between bytes of data in a serial-to-parallel converter are provided. Bits of serial data are shifted into a first register. Data bytes are then shifted out of the first register along parallel signal lines into a second register. The timing of the parallel load of data from the first register to the second register determines the parallel data byte boundary. The boundary between the parallel data bytes can be shifted using a load enable signal. The phase of the load enable signal can be changed to shift the boundary between data bytes by one or more bits. The parallel data can then be loaded from the second register into a third register. The data output signal of the third register is synchronized to a core clock signal to ensure enough set up and hold time for signals output by the third register.
摘要:
The present invention relates to a programmable low-voltage differential signaling (LVDS) output driver. The programmable LVDS output driver may include circuitry for tri-stating the output to allow several programmable LVDS output drivers to be coupled to a single receiver. The programmable LVDS output driver may also include programmable current sources for varying the output current, as well as providing additional current to circuitry within the driver (e.g., impedance circuitry). The programmable LVDS output driver may also include an impedance circuit for adjusting the output impedance of the output driver, while only diverting a small amount of source current. The current diverted by the impedance circuit may be compensated for by increasing the source current from the programmable current sources. The programmable LVDS output driver may also include pre-emphasis circuitry for boosting the edge rates of output signals.
摘要:
Input buffer circuitry for handling high-speed differential input signals on an integrated circuit is provided. The input buffer circuitry may use two parallel differential input buffers with overlapping input-voltage ranges. Logic on the integrated circuit may be powered at a core-logic power supply voltage. Input-output circuitry on the integrated circuit may be powered at an input-output voltage level. To improve the performance of the input buffers in the overlap range, at least one the input buffers can be powered using a total power supply voltage drop that exceeds the core-logic power supply level. One of the input buffers may be configured to handle lower-voltage input signals. This input buffer may be powered using the input-output power supply level.
摘要:
Input buffer circuitry for handling high-speed differential input signals on an integrated circuit is provided. The input buffer circuitry may use two parallel differential input buffers with overlapping input-voltage ranges. Logic on the integrated circuit may be powered at a core-logic power supply voltage. Input-output circuitry on the integrated circuit may be powered at an input-output voltage level. To improve the performance of the input buffers in the overlap range, at least one the input buffers can be powered using a total power supply voltage drop that exceeds the core-logic power supply level. One of the input buffers may be configured to handle lower-voltage input signals. This input buffer may be powered using the input-output power supply level.
摘要:
Circuitry is provided to individually configure each I/O of an integrated circuit to be compatible with a different LVTTL I/O standards. This can be done with only one I/O supply voltage, where that voltage is the highest of the I/O voltages needed in a particular application. The circuitry operates by regulating the output voltage of the I/O cell so that it is above the VOH and below the maximum VIH for the LVTTL standard for which it will comply with. Since each I/O cell is individually configurable, any I/O can drive out to any LVTTL specification.