US 5,394,172 AGranted

VRAM having isolated array sections for providing write functions that will not affect other array sections

AssigneeMicron Semiconductor, Inc.

InventorLoren L. McLaury

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Abstract

A video RAM having isolated array sections for providing write function that will not affect other array sections. The whole VRAM memory array does not have to be completely read before writing new pixel information to particular array section. At least two separate VRAM activities can be performed simultaneously to different parts of the array. Specifically, to write to one particular section of an array and to and for refreshing other parts of the VRAM. The overall read and write sequences can be shorter. When a particular pixel or memory cell has to be modified or update, only an associated SAM to the particular cell will be activated. This SAM will now only affect the column lines associated with that section of the array containing the activated SAM.

Claims7

Dependent claims

A video random access memory circuit, comprising:

a first memory half and a second memory array half;
a first N latch strobe line electrically associated with the first array half and electrically isolated from the second array half;
a first P latch strobe line electrically associated with the first array half and electrically isolated from the second array half;
a first N-sense amplifier circuit electrically associated with the first array half and electrically isolated from the second array half, a first N type enable signal on said first N latch strobe line controlling an activation of said first N-sense amplifier circuit;
a first P-sense amplifier circuit electrically associated with the first array half and electrically isolated from the second array half, a first P type enable signal on said P latch strobe line controlling an activation of said first P-sense amplifier circuit;
a second N latch strobe line electrically associated with the second array half and electrically isolated from the first array half;
a second P latch strobe line electrically associated with the second array half and electrically isolated from the first array half;
a second N-sense amplifier circuit, electrically associated with the second array half and electrically isolated from the first array half, a second N type enable signal on said second N latch strobe line controlling an activation of said second N-sense amplifier circuit;
and
a second P-sense amplifier circuit electrically associated with the second array half and electrically isolated from the first array half, a second P type enable signal on said second P latch strobe line controlling an activation of said second P-sense amplifier circuit.

7 more elements

A video random access memory circuit for storing information, comprising:

first column lines;
second column lines;
first memory cells, each of said first memory cells coupled to one of said first column lines;
second memory cells, each of said second memory cells coupled to one of said second column lines;
a first N-sense amplifier circuit coupled to the first column lines without being coupled to the second column lines;
a first N latch strobe line electrically coupled to the first N-sense amplifier circuit, an enable signal on said first N latch strobe line enabling said fist N-sense amplifier circuit;
a second N-sense amplifier circuit coupled to the second column lines without being coupled to the first column lines:
a second N latch strobe line electrically coupled to the second N-sense amplifier circuit, an enable signal on said second N latch strobe line enabling said second N-sense amplifier circuit;
a first P-sense amplifier circuit coupled to the first column lines without being coupled to the second column lines;
a first P latch strobe line electrically coupled to the first P-sense amplifier circuit, an enable signal on said first P latch strobe line enabling said first P-sense amplifier circuit;
a second P-sense amplifier circuit coupled to the second column lines without being coupled to the first column lines;
a second P latch strobe line electrically coupled to the second P-sense amplifier circuit, an enable signal on said second P latch strobe line enabling said second P-sense amplifier circuit, wherein each of said first and said second N latch strobe lines and each of said first and said second P latch strobe lines are electrically isolated from one another;
and wherein
the information is written to the first memory cells without electrically affecting the information in the second memory cells when said first P-sense amplifier and said first N-sense amplifier are enabled by the enable signals on the first P latch strobe line and the first N latch strobe line;
and wherein
the information is written to the second memory cells without electrically affecting the information in the first memory cells when said second P-sense amplifier and said second N-sense amplifier are enabled by the enable signals on the second P latch strobe line and the second N latch strobe line.

13 more elements

A memory device, comprising:

a) a dynamic memory array for storing dynamic data, said dynamic memory array having a first memory array portion and a second memory array portion;
b) a serial memory for storing serial data capable of transfer to said dynamic memory array for storage therein;
c) a first coupling circuit for coupling said first memory array portion and said serial memory to one another;
d) a second coupling circuit for coupling said second memory array portion and said serial memory to one another;
e) a first sensing circuit in said first memory array portion for sensing data stored and written in said first memory array portion, said first sensing circuit having a first P-sense amplifier and a first N-sense amplifier;
f) a second sensing circuit in said second memory array portion for sensing data stored and written in said second memory array portion, said second sensing circuit having a second P-sense amplifier and a second N-sense amplifier;
g) a first switching circuit comprising a first P-channel device in electrical communication with said first P-sense amplifier and comprising a first N-channel device in electrical communication with said first N-sense amplifier, an output of said first switching circuit in electrical communication with said first sensing circuit, said first sensing circuit responding to an output signal of said first switching circuit to sense the data stored and written in said first memory array portion;
and
h) a second switching circuit comprising a second P-channel device in electrical communication with said second P-sense amplifier and comprising a second N-channel device in electrical communication with said second N-sense amplifier, an output of said second switching circuit in electrical communication with said second sensing circuit, said second sensing circuit responding to an output signal of said second switching circuit to sense the data stored and written in said second memory array portion, said outputs of said first and said second switching circuits isolated from one another in order to isolate a voltage disturbance on the output of one of said first and said second switching circuits from the other of said first and said second switching circuits during a deactivation of said first and said second switching circuits;
i) an N latch node connected to a control input of said first N-channel device and a control input of said second N-channel device, said N latch node accepting an N latch signal to control an activation said first and second N-channel devices to determine when the data in said first and said second memory array portions can be sensed:
and
j) a P latch node connected to a control input of said first P-channel device and a control input of said second P-channel device, said P latch node accepting a P latch signal to control an activation of said first and said second P-channel devices to determine when the data in said first and said second memory array portions can be sensed.

9 more elements

A multi-port memory device, comprising:

a) a plurality of dynamic memory arrays for storing dynamic data, each one of said dynamic memory arrays having a first memory array portion and a second memory array portion;
b) a plurality of serial memories, each one of said serial memories in electrical communication with one of said dynamic memory arrays, said serial memories for storing serial data, said serial data capable of transfer to one of said dynamic memory arrays from a corresponding one of said serial memories for storage therein;
c) a plurality of first sensing means, each one of said first sensing means in electrical communication with one of said first memory array portions and a corresponding one of said serial memories, each of said first sensing means for sensing data stored and written in a corresponding one of said first memory array portions;
d) a plurality of second sensing means, each one of said second sensing means in electrical communication with one of said second memory arrayportions and a corresponding one of said serial memories, each of said second sensing means for sensing data stored and written in a corresponding one of said second memory array portions;
e) a plurality of first switching means, an output of each one of said first switching means in electrical communication with a corresponding one of said first sensing means, each of said first sensing means responding to an output signal of the corresponding said first switching means to sense the data stored and written in a corresponding one of said first memory array portions, said outputs of said first switching means isolated from one another;
and
f) a plurality of second switching means, an output of each one of said second switching means in electrical communication with a corresponding one of said second sensing means, each of said second sensing means responding to an output signal of the corresponding said second switching means to sense the data stored and written in a corresponding one of said second memory array portions, said outputs of said second switching means isolated from one another, wherein said output of said first and said second switching means are isolated from one another.

4 more elements

A multi-port memory device, comprising:

a) a plurality of dynamic memory arrays for storing dynamic data;
b) a plurality of serial memories, each one of said serial memories in electrical communication with a corresponding one of said dynamic memory arrays, said serial memories for storing serial data, said serial data capable of transfer from one of said serial memories to said corresponding one of said dynamic memory arrays for storage therein;
c) a plurality of first sensing means, each one of said first sensing means in electrical communication with one of said serial memories and one of said dynamic memory arrays, each of said first sensing means for sensing data stored and written in said dynamic memory array in electrical communication therewith;
d) a plurality of second sensing means, each one of said second sensing means in electrical communication with one of said serial memories and one of said dynamic memory arrays, each of said second sensing means for sensing data stored and written in said dynamic memory array in electrical communication therewith;
e) a plurality of first switching means, an output node of each one of said first switching means in electrical communication with a corresponding one of said first sensing means, each of said first sensing means responding to an output signal of the corresponding said first switching means to sense the data stored and written in one of said dynamic memory arrays, said output nodes of said first switching means isolated from one another;
and
f) a plurality of second switching means, an output node of each one of said second switching means in electrical communication with a corresponding one of said second sensing means, each of said second sensing means responding to an output signal of the corresponding said second switching means to sense the data stored and written in one of said dynamic memory memory arrays, said output nodes of said second switching means isolated from one another, wherein said output nodes of said first and said second switching means are isolated from one another.

4 more elements

Dependencies are inferred from the claim text.