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US 7,024,524 B2Granted
Semiconductor storage
AssigneeRenesas Technology Corp.
InventorKoji Nii
Life of this patent
Estimating the term…
Abstract
It is an object to obtain a semiconductor storage having a 1—chip structure which can be simultaneously accessed to memory cells present in different memory cell arrays. A 1-port memory cell array (11) provided with a word line (WL1) for a first port in common and a 2-port memory cell array (12) are provided together over one chip, thereby constituting a semiconductor storage. By selectively bringing any of a plurality of the word lines (WL1) for the first port into an active state by a row decoder (16), it is possible to simultaneously access respective memory cells of the 1-port memory cell array (11) and the 2-port memory cell array (12). By selectively bringing any of a plurality of word lines (WL2) for a second port into an active state by a row decoder (18), it is possible to singly access the 2-port memory cell array (12).
Claims18
A semiconductor storage comprising first and second memory cell arrays,
- said first memory cell array including:
- a plurality of first memory cells arranged in at least one column over a plurality of rows;
- and
- a plurality of first word lines to be connected to said first memory cells on a row unit,
- said second memory cell array including:
- a plurality of second memory cells arranged in a matrix, said second memory cells including a different number of elements than said first memory cells;
- a plurality of second word lines to be connected to said second memory cells on a row unit;
- a plurality of third word lines connected to said second memory cells on a row unit and not connected to any of said plurality of first memory cells;
- a plurality of first bit lines provided corresponding to said second memory cells on a column unit and being accessible to said second memory cell connected to said second word line in a selection state out of said plurality of second word lines;
- and
- a plurality of second bit lines provided corresponding to said second memory cells on a column unit and being accessible to said second memory cell connected to said third word line in a selection state out of said plurality of third word lines,
- said semiconductor storage further comprising:
- a first row decoder configured to select, so that a period wherein any of said first word lines is brought into a selection state based on a first address signal and a period wherein any of said second word lines is brought into a selection state based on said first address signal are overlapped.
10 more elements
A semiconductor storage comprising first and second memory cell arrays,
- said first memory cell array including:
- a plurality of first memory cells arranged in at least one column over a plurality of rows;
- and
- a plurality of first word lines to be connected to said first memory cells on a row unit,
- said second memory cell array including:
- a plurality of second memory cells arranged in a matrix;
- a plurality of second word lines to be connected to said second memory cells on a row unit;
- a plurality of third word lines connected to said second memory cells on a row unit and not connected to any of said plurality of first memory cells;
- a plurality of first bit lines provided corresponding to said second memory cells on a column unit and being accessible to said second memory cell connected to said second word line in a selection state out of said plurality of second word lines;
- and
- a plurality of second bit lines provided corresponding to said second memory cells on a column unit and being accessible to said second memory cell connected to said third word line in a selection state out of said plurality of third word lines,
- said semiconductor storage further comprising:
- a first row decoder for simultaneously bringing any of said first word lines and any of said second word lines into a selection state based on a first address signal;
- a second row decoder for bringing any of said plurality of third word lines into a selection state based on a second address signal;
- and
- a third memory cell array having a plurality of second dummy cells arranged in at least a column over a plurality of rows, said first and third memory cell arrays being formed integrally with said second memory cell array interposed therebetween and the number of accessible ports of said second dummy cell being set to be smaller than that of accessible ports of said memory cells for a real operation,
- said memory cells for a real operation including a memory cell having a 2-port structure with first and second ports which are accessible,
- said first and second dummy cells including a memory cell having a 1-port structure with first and second dummy ports which are accessible,
- said first ports of said plurality of memory cells for a real operation and said first dummy ports of said plurality of first dummy cells being connected to said plurality of common word lines on a row unit in common,
- said second ports of said plurality of memory cells for a real operation and said second dummy ports of said plurality of second dummy cells being connected to said plurality of third word lines on a row unit in common,
- said first row decoder including a row decoder provided in the vicinity of said first memory cell array, and
- said second row decoder including a row decoder provided in the vicinity of said third memory cell array.
19 more elements
A semiconductor storage comprising first and second memory cell arrays,
- said first memory cell array including:
- a plurality of first memory cells arranged in at least one column over a plurality of rows;
- and
- a plurality of first word lines to be connected to said first memory cells on a row unit,
- a plurality of second word lines to be connected to said first memory cells on a row unit,
- a plurality of first bit lines provided corresponding to said first memory cells on a column unit and being accessible to said first memory cell connected to said first word line in a selection state out of said plurality of first word lines;
- and
- a plurality of second bit lines provided corresponding to said first memory cells on a column unit and being accessible to said first memory cell connected to said second word line in a selection state out of said plurality of second word lines,
- said second memory cell array including:
- a plurality of second memory cells arranged in a matrix, said second word lines not being connected to any of said second memory cells;
- a plurality of third word lines to be connected to said second memory cells on a row unit;
- a plurality of fourth word lines connected to said second memory cells on a row unit and not connected to any of said first memory cells;
- a plurality of third bit lines provided corresponding to said second memory cells on a column unit and being accessible to said second memory cell connected to said third word line in a selection state out of said plurality of third word lines;
- and
- a plurality of fourth bit lines provided corresponding to said second memory cells on a column unit and being accessible to said second memory cell connected to said fourth word line in a selection state out of said plurality of fourth word lines,
- said semiconductor storage further comprising:
- a first row decoder configured to select so that a period wherein any of said first word lines is brought into a selection state based on a first address signal and a period wherein any of said third word lines is brought into a selection state based on said first address signal are overlapped,
- a second row decoder configured to bring any of said of second word lines into a selection state based on a second address signal;
- and
- a third row decoder configured to bring any of said of fourth word lines into a selection state based on a third address signal, wherein
- said first memory cell includes a memory cell having a 2-port structure which can be accessed by a first port and a second port,
- said second memory cell including a memory cell having a 2-port structure which can be accessed by said first port and a third port which is different from said second port,
- an access to be carried out by setting said first and third word lines into a selection state by said first row decoder including an access to be preformed by said first port,
- an access to be carried out by setting said second word line into a selection state by said second row decoder including an access to be performed by said second port, and
- an access to be carried out by setting said fourth word line into a selection state by said third row decoder including an access to be performed by said third port.
22 more elements
Dependencies are inferred from the claim text.