摘要:
According to the present invention, there is provided a semiconductor device including a power supply circuit which receives an external power supply voltage supplied, and outputs an internal power supply voltage not higher than the external power supply voltage; a system module which receives the internal power supply voltage, and performs a predetermined operation; and a performance monitor circuit which measures a processing speed of said system module when the internal power supply voltage is applied, and, on the basis of the processing speed, outputs a first control signal which requests to set the external power supply voltage at a first level, and a second control signal which requests said power supply circuit to set the internal power supply voltage at a second level. The power supply circuit outputs the internal power supply voltage having the second level on the basis of the second control signal applied thereto.
摘要:
According to the present invention, there is provided a semiconductor device comprising: a power supply circuit which receives an external power supply voltage supplied, and outputs an internal power supply voltage not higher than the external power supply voltage; a system module which receives the internal power supply voltage, and performs a predetermined operation; and a performance monitor circuit which measures a processing speed of said system module when the internal power supply voltage is applied, and, on the basis of the processing speed, outputs a first control signal which requests to set the external power supply voltage at a first level, and a second control signal which requests said power supply circuit to set the internal power supply voltage at a second level, wherein said power supply circuit outputs the internal power supply voltage having the second level on the basis of the second control signal applied thereto.
摘要:
This invention relates to P- and N-well regions where inverters constituting an SRAM cell are formed. The P-well region is divided into two parts, which are laid out on the two sides of the N-well region. Boundaries (BL11, BL12) are formed to run parallel to bit lines (BL, /BL). With this layout, diffusion layers (ND1, ND2) within the P-well regions can be formed into simple shapes free from any bent portion, reducing the cell area.
摘要:
A semiconductor device of the present invention includes a bipolar transistor and MOS transistors which are formed on the same semiconductor substrate. The bipolar transistor is heterojunction transistor having a hetero junction. The hetero-bipolar transistor is a bipolar transistor of double-hetero structure in which a material used for forming the base region thereof has a band gap narrower than a material used for forming the emitter and collector regions thereof.
摘要:
Memory cell arranged in a matrix configuration are selected by a particular word line to supply the stored data to particular bit lines. The row address decoder selects a particular word line based on the address signal, while the column address decoder selects particular bit lines based on the address signal. Each of the row address decoder and column address decoder contains a first decoder for decoding the address signal, a delay circuit for delaying the output from the first decoder when data is written into the memory cell, and a second decoder for receiving the output signals from the first decoder and delay circuit and based on these signals, selecting either a particular word line or particular bit lines.
摘要:
In a selected column, a pull-up transistor pair is not selected but, instead, a transmission gate transistor pair is selected. In the read mode, the transmission gate transistor pair serves as pull-up loads between the bit line pair. However, the transmission gate transistor pair is kept off until the voltage across the bit line pair is decreased from the power supply potential level to the threshold voltage level of the transmission gate transistors. Therefore, no DC current path is formed in the bit line pair when the voltage across the bit line pair is within a range from a voltage equal to the power supply potential level to a potential lower than the power supply potential by an amount equal to the threshold voltage level, and the rate of increase of a potential difference across the bit line pair is determined by a pull-in current of the memory cell. Therefore, a high-speed sense operation can be realized. In the write mode, the transmission gate transistor pair serves a bit line pull-up function. Since no normally-ON bit line load transistor is arranged, no direct current path including the bit line pair is present, and hence, low power consumption can be achieved.
摘要:
The threshold voltage of bit line percharge/equalize MOS transistors is smaller than that of normally ON type bit line pull-up transistors. With this feature, there is no current flows through a bit line from power source V.sub.DD during a read-out operation. The voltage difference between a pair of bit lines can be increased at high speed, thereby increasing the read-out speed.
摘要:
A first and second barrel shifters (BSA0 and BSA1) are connected directly without intervening any pipe-line register between the two, and a sense amplifier (R3A0) is provided at an output side of the second barrel register (BSA1). Further, the circuit patterns of the first and second barrel shifters are formed being overlapped with each other in such a way that the elements of one of the first and second barrel shifters are formed at the dead space of the other of the two barrel shifters to reduce the pattern area. In the shift circuit and the variable-length decoder, the data lines of the barrel shifters can be minimized in size and width.
摘要:
A first threshold value for detecting a potential indicating a read state, and a second threshold value for detecting a write state are set in an inverter circuit, to which a read/write signal R/W for setting the state of a memory cell is supplied, by means of a P-channel transistor, an N-channel transistor, and another P-channel transistor which is much smaller in gate width than the above transistors. The first or second threshold value is selected by a logic circuit constituted by an inverter circuit and a delay circuit in accordance with the level of the read/write signal R/W. Therefore, a change from a read state to a write state and a reverse change can be detected at high speed, thus providing a read/write control circuit for a random access memory, which can increase the speed of a read operation immediately after a write operation while ensuring a sufficient data write time, and can shorten the write recovery time.
摘要:
A CMOS static memory includes a memory cell array having a plurality of memory cells two-dimensionally arranged in word and bit line directions, and peripheral circuits including n-type MOSFETs for performing a write/read operation for the memory cell. The memory cell includes a flip-flop circuit constituted by a pair of pull-down n-type MOSFETs and a pair of pull-up resistor elements, and a pair of transmission gate n-type MOSFETs. Each of a pair of pull-down n-type MOSFETs and the pair of transmission gate n-type MOSFETs have a gate oxide film having a thickness and gate length which are smaller than those of a gate oxide film of each n-type MOSFET in the peripheral circuits.