Abstract: A semiconductor device including a level converter (LSC) is disclosed. The level converter comprises a voltage-up circuit (LSC1) that operates on low voltage of power supply (VDD) and steps up voltage enough to drive the level converter and a level converter circuit (LSC2) that operates on high voltage of power supply (VDDQ). The voltage-up circuit is capable of constantly generating 2×VDD so that the level converter can convert a low voltage of power supply (VDD) below 1 V to VDDQ. This voltage-up circuit can be configured only with MOSFET transistors produced by thin oxide film deposition, thus enabling high-speed operation. To facilitate designing a circuit for preventing a leakage current from occurring in the level converter during sleep mode of a low-voltage-driven circuit (CB1), the level converter circuit (LSC2) includes a leak protection circuit (LPC) that exerts autonomous control for leak prevention, dispensing with external control signals.

Abstract: The present invention provides a sense circuit for DRAM memory cell to cover the events that a sense time becomes remarkably longer when a power source voltage is lowered, a sense time under the low voltage condition becomes shorter when temperature rises and a sense time changes to a large extent for fluctuation of processes. The present invention provides the following typical effects. A switch means is provided between the bit line BL and local bit line LBL connected to the memory cells for isolation and coupling of these bit lines. The bit line BL is precharged to the voltage of VDL/2, while the local bit line LBL is precharged to the voltage of VDL. The VDL is the maximum amplitude voltage of the bit line BL. A sense amplifier SA comprises a first circuit including a differential MOS pair having the gate connected to the bit line BL and a second circuit connected to the local bit line LBL for full amplitude amplification and for holding the data.

Abstract: A semiconductor integrated circuit that is well-balanced between increased operating speed and decreased power consumption caused by a leakage current. The gate cells of the circuit comprised of low threshold voltage MOSs are used for logic gates provided with three or more inputs, and gate cells comprised of high threshold voltage MOSs are generally used for logic gates provided with one or two inputs, sometimes on a case-by-case basis.

Abstract: A semiconductor device including a level converter (LSC) is disclosed. The level converter comprises a voltage-up circuit (LSC1) that operates on low voltage of power supply (VDD) and steps up voltage enough to drive the level converter and a level converter circuit (LSC2) that operates on high voltage of power supply (VDDQ). The voltage-up circuit is capable of constantly generating 2×VDD so that the level converter can convert a low voltage of power supply (VDD) below 1 V to VDDQ. This voltage-up circuit can be configured only with MOSFET transistors produced by thin oxide film deposition, thus enabling high-speed operation. To facilitate designing a circuit for preventing a leakage current from occurring in the level converter during sleep mode of a low-voltage-driven circuit (CB1), the level converter circuit (LSC2) includes a leak protection circuit (LPC) that exerts autonomous control for leak prevention, dispensing with external control signals.

Abstract: A semiconductor integrated circuit device provided with a first circuit block BLK1, a second circuit block DRV1 and a conversion circuit MIO1 for connecting the first circuit block to the second circuit block. The first circuit block includes a first mode for applying a supply voltage and a second mode for shutting off the supply voltage. The conversion circuit is provided with a function for maintaining the potential of an input node of the second circuit block at an operation potential, thereby suppressing a penetrating current flow when the first circuit block is in the second mode. The conversion circuit (MIO1 to MIO4) are commonly used for connecting circuit blocks.

Abstract: To provide means that can hide refresh operations even when the data width of a cache line differs from that of the external data bus in a memory that uses a cache memory and a DRAM consisting of a plurality of banks. A semiconductor device consisting of a plurality of memory banks BANK0 to BANK127, each consisting of a plurality of memory cells, as well as a cache memory CACHEMEM used to retain information read from the plurality of memory banks. The cache memory CACHEMEM consists of a plurality of entries, each having a data memory DATAMEM and a tag memory TAGMEM. The data memory DATAMEM consists of a plurality of sub lines DATA0 to DATA3 and the tag memory TAGMEM Consists of a plurality of valid bits V0 to V3 and a plurality of dirty bits D0 to D3. It is possible to realize a memory with excellent operability, causing no refresh operation to delay external accesses. In other words, it is possible to realize a memory compatible with an SRAM in which refresh operations are hidden from external.

Abstract: In a low power consumption mode in which prior data is retained upon power shutdown, the return speed thereof is increased. While use of an existent data retaining flip-flop may be considered, this is not preferred since it increases area overhead such as enlargement of the size of a cell. A power line for data retention for power shutdown is formed with wirings finer than a usual main power line. Preferably, power lines for a data retention circuit are considered as signal lines and wired by automatic placing and mounting. For this purpose, terminals for the power line for data retention are previously designed by providing the terminals therefor for the cell in the same manner as in the existent signal lines. Additional layout for power lines is no longer necessary for the cell, which enables a decrease in the area and design by an existent placing and routing tool.

Abstract: To enhance the speed of first access (read access different in word line from the previous access) to a multi-bank memory, multi-bank memory macro structures are used. Data are held in a sense amplifier for every memory bank. When access is hit to the held data, data latched by the sense amplifier are output to thereby enhance the speed of first access to the memory macro structures. Namely, each memory bank is made to function as a sense amplifier cache. To enhance the hit ratio of such a sense amplifier cache more greatly, an access controller self-prefetches the next address (an address to which a predetermined offset has been added) after access to a memory macro structure so that data in the self-prefetched address are preread by a sense amplifier in another memory bank.

Abstract: A semiconductor integrated circuit device provided with a first circuit block BLK1, a second circuit block DRV1 and a conversion circuit MIO1 for connecting the first circuit block to the second circuit block. The first circuit block includes a first mode for applying a supply voltage and a second mode for shutting off the supply voltage. The conversion circuit is provided with a function for maintaining the potential of an input node of the second circuit block at an operation potential, thereby suppressing a penetrating current flow when the first circuit block is in the second mode. The conversion circuit (MIO1 to MIO4) are commonly used for connecting circuit blocks.

Abstract: A semiconductor integrated circuit is disclosed, in which a memory is activated at high speed in commensurate with a high-speed logic circuit mounted with the memory in order to reduce the cost using a DRAM of a 3-transistor cell requiring no capacitor. A pair of data lines connected with a plurality of memory cells having the amplification function are set to different precharge voltage values, thereby eliminating the need of a dummy cell. The elimination of the need of the dummy cell unlike in the conventional DRAM circuit using a gain cell reduces both the required space and the production cost. A hierarchical structure of the data lines makes a high-speed operation possible. Also, a DRAM circuit can be fabricated through a fabrication process matched with an ordinary logic element.

Abstract: A dynamic memory requires refreshing to retain data in its memory cells. This may cause access to the dynamic memory for purposes other than refreshing (external access) and access to it for refreshing to compete with each other, resulting in a performance deterioration. According to this invention, a pipelined dynamic memory (PDRAM) is used, and the pipeline frequency (CLK) of the pipelined dynamic memory is made higher than the frequency (CLK1) of external access, and access required for refreshing is made to an unoccupied slot (a timing when any external access request is never issued) in the pipeline of the pipelined dynamic memory. This makes refreshing of the internal dynamic memory an internal operation, which eliminates the need to take refreshing into consideration at the time external access is made, leading to improvement in operating ease and speed.

Abstract: A semiconductor device is designed to hide refresh operations even when the data width of a cache line differs from that of the external data bus in a memory that uses a cache memory and a DRAM with a plurality of banks. The semiconductor device includes a plurality of memory banks BANK0 to BANK127, each having a plurality of memory cells, as well as a cache memory CACHEMEM used to retain information read from the plurality of memory banks. The cache memory CACHEMEM includes a plurality of entries, each having a data memory DATAMEM and a tag memory TAGMEM. The data memory DATAMEM has a plurality of sub lines DATA0 to DATA3 and the tag memory TAGMEM has a plurality of valid bits V0 to V3 and a plurality of dirty bits D0 to D3.

Abstract: To enhance the speed of first access (read access different in word line from the previous access) to a multi-bank memory, multi-bank memory macro structures are used. Data are held in a sense amplifier for every memory bank. When access is hit to the held data, data latched by the sense amplifier are output to thereby enhance the speed of first access to the memory macro structures. Namely, each memory bank is made to function as a sense amplifier cache. To enhance the hit ratio of such a sense amplifier cache more greatly, an access controller self-prefetches the next address (an address to which a predetermined offset has been added) after access to a memory macro structure so that data in the self-prefetched address are preread by a sense amplifier in another memory bank.

Abstract: A semiconductor device includes a differential level converter circuit that receives a first signal and outputs a second signal of greater amplitude. The differential level converter has a first MISFET pair for receiving the first signal, a second MISFET pair for enhancing the withstand voltage of the first MISFET pair, and a third MISFET pair with cross-coupled gates for latching the second signal from output. The film thickness of the gate insulating films of the second and third MISFET pairs is made thicker than that of the first MISFET pair, and the threshold voltages of the first and second MISFET pairs are made smaller than that of the third MISFET pair. This level converter circuit operates at high speed even if there is a large difference in the signal amplitude before and after level conversion.

Abstract: A semiconductor integrated circuit is disclosed, in which a memory is activated at high speed in commensurate with a high-speed logic circuit mounted with the memory in order to reduce the cost using a DRAM of a 3-transistor cell requiring no capacitor. A pair of data lines connected with a plurality of memory cells having the amplification function are set to different precharge voltage values, thereby eliminating the need of a dummy cell. The elimination of the need of the dummy cell unlike in the conventional DRAM circuit using a gain cell reduces both the required space and the production cost. A hierarchical structure of the data lines makes a high-speed operation possible. Also, a DRAM circuit can be fabricated through a fabrication process matched with an ordinary logic element.

Abstract: The present invention provides a sense circuit for DRAM memory cell to cover the events that a sense time becomes remarkably longer when a power source voltage is lowered, a sense time under the low voltage condition becomes shorter when temperature rises and a sense time changes to a large extent for fluctuation of processes. The present invention provides the following typical effects. A switch means is provided between the bit line BL and local bit line LBL connected to the memory cells for isolation and coupling of these bit lines. The bit line BL is precharged to the voltage of VDL/2, while the local bit line LBL is precharged to the voltage of VDL. The VDL is the maximum amplitude voltage of the bit line BL. A sense amplifier SA comprises a first circuit including a differential MOS pair having the gate connected to the bit line BL and a second circuit connected to the local bit line LBL for full amplitude amplification and for holding the data.

Abstract: To enhance the speed of first access (read access different in word line from the previous access) to a multi-bank memory, multi-bank memory macro structures are used. Data are held in a sense amplifier for every memory bank. When access is hit to the held data, data latched by the sense amplifier are output to thereby enhance the speed of first access to the memory macro structures. Namely, each memory bank is made to function as a sense amplifier cache. To enhance the hit ratio of such a sense amplifier cache more greatly, an access controller self-prefetches the next address (an address to which a predetermined offset has been added) after access to a memory macro structure so that data in the self-prefetched address are preread by a sense amplifier in another memory bank.

Abstract: In an information processing apparatus involving a cache accessed by INDEX and TAG addresses, accesses to the main memory include many accesses attributable to the local character of referencing and write-back accesses attributable to the replacement of cache contents. Accordingly, high speed accessing requires efficient assignment of the two kinds of accesses to banks of the DRAM.

Abstract: OF THE DISCLOSURE A dynamic memory requires refreshing to retain data in its memory cells. This may cause access to the dynamic memory for purposes other than refreshing (external access) and access to it for refreshing to compete with each other, resulting in a performance deterioration. According to this invention, a pipelined dynamic memory (PDRAM) is used, and the pipeline frequency (CLK) of the pipelined dynamic memory is made higher than the frequency (CLK1) of external access, and access required for refreshing is made to an unoccupied slot (a timing when any external access request is never issued) in the pipeline of the pipelined dynamic memory. This makes refreshing of the internal dynamic memory an internal operation, which eliminates the need to take refreshing into consideration at the time external access is made, leading to improvement in operating ease and speed.

Abstract: A semiconductor integrated circuit that is well-balanced between increased operating speed and de creased power consumption caused by a leakage current. The gate cells of the circuit comprised of low threshold voltage MOSs are used for logic gates provided with three or more inputs, and gate cells comprised of high threshold voltage MOSs are generally used for logic gates provided with one or two inputs, sometimes on a case-by-case basis.