Miscellaneous active electrical nonlinear devices – circuits – and – Signal converting – shaping – or generating – Particular stable state circuit
Reexamination Certificate
2002-03-07
2003-03-18
Cunningham, Terry D. (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Signal converting, shaping, or generating
Particular stable state circuit
C327S200000, C365S203000
Reexamination Certificate
active
06535041
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates to dynamic strobe circuits used in data processors to implement logical functions. A dynamic strobe circuit according to the invention includes an improved dynamic node keeper arrangement that reduces power consumption without significantly affecting circuit performance.
BACKGROUND OF THE INVENTION
Dynamic strobe circuits are widely used in data processors because of their speed advantage in implementing logical AND functions utilizing a large number of inputs, commonly referred to as “wide” AND functions. In particular, dynamic strobe circuits are used in decoders, programmable logic arrays, address comparators, and adders. These processor components or macros are major components of the processor and some are used repeatedly in a single processor.
FIG. 1
illustrates a typical prior art dynamic strobe circuit
100
. This prior art dynamic strobe circuit includes a dynamic node
101
connected to a precharge device
102
comprising a P-type field effect transistor (“FET”). Dynamic node
101
is also connected to a number of the pull-down devices
103
, each comprising a N-type FET. Dynamic strobe circuit
100
also includes a strobe component
104
made up of a P-type FET
105
, a N-type FET
106
, and an input device
107
which comprises a N-type FET. Devices
105
and
106
each receive a strobe signal S at their respective gate, while input device
107
receives the signal present on dynamic node
101
. The signal at the dynamic node represents the input to strobe component
104
, while the output of the strobe component is taken at the junction between P-type device
105
and input device
107
. This strobe component output is connected to an intermediate node or strobe dynamic node
108
. The signal at intermediate node
108
is inverted by inverter
109
and applied as the output of the dynamic strobe circuit at circuit output node
110
. This output signal is fed back to control an output keeper device, P-type FET
111
.
The prior art strobe circuit shown in
FIG. 1
includes a keeper arrangement
112
for dynamic node
101
. This prior art keeper arrangement
112
includes an inverter
114
connected to receive the signal at dynamic node
101
, and to apply the inverted signal to control a keeper device, P-type FET
115
. A drawback of this prior art keeper arrangement
112
is that keeper device
115
is on or active any time dynamic node
101
is at a logical high voltage level. Thus, keeper device
115
is normally conductive and dissipating power, even during the precharge period.
SUMMARY OF THE INVENTION
A dynamic strobe circuit according to the invention includes an improved dynamic node keeper arrangement. The improved dynamic node keeper arrangement includes a keeper device that is controlled by the signal at the intermediate node, that is, the signal at the output of the strobe component. By controlling the dynamic node keeper device through the strobe component output, the keeper device is active or conductive only when necessary to protect against noises in the pull-down network. At all other times in the course of operation of the dynamic strobe circuit, the dynamic node keeper device according to the invention is nonconductive or inactive. Thus, the dynamic strobe circuit according to the invention reduces power consumption. The present dynamic node keeper arrangement also eliminates the inverter required to provide the control signal in the prior art keeper arrangement, and thus reduces the number of devices in the circuit. These benefits are obtained without any significant impact on circuit performance.
The invention includes a method for controlling the dynamic node of a dynamic strobe circuit to decrease power consumption in the circuit. The method includes first precharging the dynamic node of the circuit during a precharge period, and then selectively connecting the dynamic node to the supply voltage through the keeper device in response to, or under the control of, the strobe component output. Controlling the dynamic node keeper device by the strobe component output ensures that the keeper device is in its conductive state, and thus dissipating power, only when necessary to protect the dynamic node from spurious signals to the draw-down devices.
These and other objects, advantages, and features of the invention will be apparent from the following description of the preferred embodiments, considered along with the accompanying drawings.
REFERENCES:
patent: 5973529 (1999-10-01), Chappell et al.
patent: 6072746 (2000-06-01), Durham et al.
patent: 6326814 (2001-12-01), Stasiak et al.
patent: 6369629 (2002-04-01), Sato
Bucki Robert John
Dhong Sang Hoo
Fischer Jeffrey Herbert
Silberman Joel Abraham
Takahashi Osamu
Culbertson Russell D.
Cunningham Terry D.
Nguyen Long
Salys Casimer K.
Shaffer & Culbertson L.L.P.
LandOfFree
Strobe circuit keeper arrangement providing reduced power... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Strobe circuit keeper arrangement providing reduced power..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Strobe circuit keeper arrangement providing reduced power... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3076803