Browse Prior Art Database

Multiple Wordline Control Scheme DRAM With Single RAS Input

IP.com Disclosure Number: IPCOM000099310D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 3 page(s) / 87K

Publishing Venue

IBM

Related People

Katayama, Y: AUTHOR [+3]

Abstract

Disclosed is a Multiple wordline control scheme DRAM (Dynamic Random-Access Memory) with only single RAS Address Strobe) input. This is achieved by the Island concept which latches the address at both the rising falling edges of the RAS signal.

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Multiple Wordline Control Scheme DRAM With Single RAS Input

       Disclosed is a Multiple wordline control scheme DRAM
(Dynamic Random-Access Memory) with only single RAS Address Strobe)
input.  This is achieved by the Island concept which latches the
address at both the rising falling edges of the RAS signal.

      Fig. 1 shows the difference between a conventional DRAM the new
scheme. In the new scheme, the DRAM chip is into independent segments
(called Islands) which can as independent DRAMs with independent row
addresses The Island address is used to select one of the for the
activation. The number of local RAS, RAS#n, is identical to the
number of Islands in the chip.

      Fig. 2 shows the generation of local RAS clocks from the  input
to the chip by decoding Island addresses. The addresses are decoded
in both the leading and edges of the RAS clock to the chip. This
Island is also decoded at the CAS (Column Address Strobe) edge to
select the column portion.

      With the architecture above, the chip can operate in a
array-access mode, controlling multiple wordlines a proper selection
of RAS CAS and address inputs, as in Fig. 3(a). The advantage is that
several pages of data in the chip can be accessed by only the island
and column addresses and providing The conventional random-access and
page-access mode is allowed by changing RAS CAS and address inputs,
as in Fig. 3(b).  In the scheme can precharge all memory arrays the
same cycle. Fig. 4(a)...