US 5,295,254 AGranted

Semiconductor memory device cell array divided into a plurality of blocks

AssigneeKabushiki Kaisha Toshiba

InventorYoshinori Ogawa

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Abstract

There is disclosed a semiconductor memory device as a multi-port DRAM having split SAM registers. This memory device comprises a RAM section of which memory area is halved into first and second cell arrays by the value of a specific bit constituting a portion of a column address, a SAM section comprised of first and second registers, first and second data transfer paths for carrying out data transfer from the first and second cell arrays to the first and second registers, respectively, third and fourth data transfer paths for shifting data from the first and second cell arrays to the second and first data transfer paths, respectively, and first, second third and fourth transfer controllers are inserted into the first, second third and fourth data transfer paths, respectively. Thus, with this multi-port DRAM, the degree of freedom of mapping is improved in a frame buffer.

Claims6

Dependent claims

A semiconductor memory device comprising:

a RAM section in which the memory area is halved into a first cell array and a second cell array by the value of a specific bit constituting a portion of a column address,
a SAM section comprised of first and second registers,
a first data transfer path for carrying out data transfer from said first cell array to said first register,
a first transfer control means inserted into said first data transfer path,
a second data transfer path for carrying out data transfer from said second cell array to said second register,
a second transfer control means inserted into said second data transfer path,
a third data transfer path for shifting data from said first cell array to said second data transfer path,
a third transfer control means inserted into said third data transfer path,
a fourth data transfer path for shifting data from said second cell array to said first data transfer path, and
a fourth transfer control means inserted into said fourth data transfer path.

7 more elements

Dependencies are inferred from the claim text.