Semiconductor device including multi-chip
AssigneeHitachi, Ltd.
InventorsKazushige Ayukawa, Seiji Miura, Yoshikazu Saitou
Life of this patent
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Abstract
In order to implement a memory having a large storage capacity and a reduced data retention current, a non-volatile memory, an SRAM, a DRAM, and a control circuit are modularized into one package. The control circuit conducts assignment of addresses to the SRAM and DRAM, and stores data that must be retained over a long period of time in the SRAM. In the DRAM, a plurality of banks are divided into two sets, and mapped to the same address space, and sets are refreshed alternately. A plurality of chips of them are stacked and disposed, and wired by using the BGA and chip-to-chip bonding.
Claims4
A semiconductor device comprising:
- a first semiconductor chip comprising a plurality of DRAM memory cells;
- a second semiconductor chip comprising a plurality of SRAM memory cells;
- wherein pads of said first and second semiconductor chips are connected with wirings and molded in a first package;
- a memory controller;
- and
- wherein during a first mode, said memory controller does not supply power to said first semiconductor chip, and saves data in said SRAM memory cells of said second semiconductor chip.
A semiconductor device comprising:
- a first semiconductor chip comprising a plurality of DRAM memory cells;
- a second semiconductor chip comprising a plurality of SRAM memory cells;
- wherein pads of said first and second semiconductor chips are connected with wirings and molded in a first package;
- wherein said plurality of DRAM memory cells are divided in a first bank and a second bank;
- wherein during a first period, said DRAM memory cells in said first bank are used for a read/write operation and said DRAM memory cells in said second bank are used for a refresh operation;
- and
- wherein during a second period, said DRAM memory cells in said first bank are used for a refresh operation and said DRAM memory cells in said second bank are used for a read/write operation.
Dependencies are inferred from the claim text.