Pipelined memory chip structure having improved cycle time

• US 4,845,677 A
• Filed: 08/17/1987
• Issued: 07/04/1989
• Est. Priority Date: 08/17/1987
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Schuster, Stanley E., Chappell, Terry I., Chappell, Barbara A.
• Primary Examiner(s): Hecker, Stuart N.
• Assistant Examiner(s): Bowler, Alyssa H.
• Application Number:
  US07/086,136
• Time in Patent Office: 687 Days
• Field of Search: 365/230, 365/187, 365/233, 365/203
• US Class Current: 365/189.02
• CPC Class Codes: G11C 7/1039 using pipelining techniques, i.e. using latches between functional memory parts, e.g. row/column decoders, I/O buffers, sense amplifiers
• CPC Class Codes: G11C 7/12 Bit line control circuits, e.g. drivers, boosters, pull-up circuits, pull-down circuits, precharging circuits, equalising circuits, for bit lines
• CPC Class Codes: G11C 8/12 Group selection circuits, e.g. for memory block selection, chip selection, array selection

Abstract

A semiconductor random access memory chip wherein the cycle time is less than the access time for any combination of read or write sequence. The semiconductor random access memory chip is partitioned into relatively small sub-arrays with local decoding and precharging. The memory chip operates in a pipelined manner with more than one access propagating through the chip at any given time and wherein the cycle time is limited by sub-array cycles wherein the cycle time is less than the access time for a memory chip having cycle times greater than access times for accesses through the same sub-array. The memory chip also incorporates dynamic storage techniques for achieving very fast access and precharge times.

Claims

1. A piplined semiconductor 2ⁿ Kbit memory chip, n being an integer not less than 2, said chip being segmented into a plurality of 2^n-y memory sub-arrays of 2^y Kbits arranged in columns and rows on said chip, each one of said 2^n-y memory sub-arrays includes a separate associated word line driver circuit means, sense amplifier circuit means and independent precharge circuit means connected thereto, each of said independent precharge circuit means of each of said segmented memory sub-arrays providing local self-timed reset and precharge function for each segmented memory array independent of said other of said plurality of 2^n-y memory arrays,

wherein said memory chip exhibits an access time t for providing data from said memory chip and wherein said local reset and precharge circuits of each of said segmented memory sub-arrays provides a cycle time for each sub-array which is less than chip access time t.

2. A pipelined semiconductor 2ⁿ Kbit memory chip according to claim 1 wherein said segmented memory sub-arrays including independent local decoding and precharging means operate in a pipelined manner with greater than one access propagating through said 2ⁿ Kbit memory chip at one time.

3. A pipelined semiconductor 2ⁿ Kbit memory chip according to claim 2 further including row and column address circuits disposed on said chip connected to said word line and bitswitch decoder/driver circuit means and responsive to input address access signals for selecting ones of said 2^n-y segmented memory sub-arrays for access.

4. A pipelined semiconductor 2ⁿ Kbit memory chip according to claim 1 further including compare circuits for comparing at least two signals for determining said sub-arrays being accessed by separate access signals.

5. A pipelined semiconductor 2ⁿ Kbit memory chip according to claim 1 wherein said memory chip exhibits an access time t, further including global blocks on said chip external to said sub-arrays each containing clock circuit means, address buffer means, row decoder means, data output buffer means and word driver means associated with said plurality of sub-arrays,

each of said global blocks including separate reset and precharge circuit means for providing a cycle time for each of said global blocks which is less than chip access time t.