摘要:
Dummy cells are divided into a plurality of divided dummy columns, and divided dummy bit lines are arranged corresponding to the divided dummy columns. These divided dummy bit lines are provided with dummy sense amplifiers that drive a sense control line transmitting a sense enable signal activating a sense amplifier. A faster activation timing of the sense amplifier can be achieved.
摘要:
The dummy cell of the SRAM corresponds to a normal memory cell of which first and second P-channel MOS transistors for loading are replaced by the first and the second N-channel MOS transistors, of which gate and source are provided with power supply potential and ground potential, respectively. When a word line rises to “H” level, third and fourth N-channel MOS transistors for accessing are rendered conductive, to pass current from dummy bit line to a line of ground potential via the third N-channel MOS transistor, the first N-channel MOS transistor, and a fifth N-channel MOS transistor for driving. Accordingly, speed of potential decrease of the dummy bit line may be faster than that of bit line. Hence, operational timing can easily be optimized, and operational margin can be increased.
摘要:
Dummy cells each having the same layout as a normal memory cell are aligned in a row direction to the normal memory cells, and are arranged in rows and columns. In each dummy cell column, a dummy bit line is arranged, and a plurality of dummy cells are simultaneously selected and connected to the corresponding dummy bit line when one word line is selected. A voltage detecting circuit detects the potentials on the dummy bit lines to determine timing of activation of a sense amplifier. In the semiconductor memory device, the potential on the dummy bit line can be changed at high speed, and internal data read timing can be optimized independent of a structure of a memory cell array.
摘要:
In a PLL circuit including a plurality of VCOs, first and second switches are respectively connected between the gate and source and the gate and drain of a P channel MOS transistor included in a current mirror circuit of each VCO. In a VCO which is employed, only the second switch is turned on to allow a control current to flow. In a VCO which is not employed, only the first switch is turned on to cut off the control current. Compared with a conventional circuit in which all of the plurality of VCOs are always producing oscillations, the power consumption is reduced.
摘要:
First and second pattern data constituting cursor pattern data are stored separately in banks (101a, 101b). A cursor memory body (101) simultaneously outputs the first and second pattern data from the banks (101a, 101b). Therefore, a read circuit (102) can simultaneously output the first and second pattern data through a port (P2) with a simple control. With this configuration, an easy-controllable cursor memory can be provided.
摘要:
Disclosed is a semiconductor integrated circuit device of a gate array system making it possible to mount a digital circuit and a high-precision analog circuit on a common substrate. This semiconductor integrated circuit device includes a basic cell array formed by a plurality of NMOS transistors and a plurality of PMOS transistors formed in rows on a semiconductor substrate. The basic cell array includes a plurality of N well regions formed in rows on the semiconductor substrate, P well regions and well terminal regions. The P well regions or N well regions are divided into small regions of the other conductivity type.
摘要:
When a pair of word lines 1 and 2 change from a selected state to a non selected state, a word line discharging circuit 10 enables a transistor 15 to conduct during a period when this pair of word lines 1 and 2 are maintained at the highest potential compared with the other pairs of word lines, so that the pair of word lines 1 and 2 are discharged by means of a first discharging current source 11. The word line discharging circuit 10 enables a transistor 16 to conduct after another pair of word lines attain the highest potential, so that the pair of word lines 1 and 2 are discharged by means of a second discharging current source 12.
摘要:
In a bus circuit which includes a plurality of signal lines, insertion pattern &agr;, which provides repeaters in only an odd numbered series of signal lines, and insertion pattern &bgr;, of which the segment length is equal to that of pattern &agr; and which provides repeaters to only an even numbered series of signal lines, are arranged in an alternating manner in accordance with the length of the signal lines. As a result, the segments during which data signals on the neighboring signal lines run together in opposite phases become half the entire length of the signal lines. Therefore, this bus circuit can prevent the operational speed from becoming slowed.
摘要:
Even if a power supply potential VDD of a core section is set in an off state, a latch of a level conversion circuit holds a value corresponding to an output. It is, therefore, possible for a semiconductor device to hold an output state of an output node. Thereafter, an enable signal is deactivated, whereby the output node can be set in a high impedance state and a bus or the like can be released to the other device.
摘要:
Provided is a semiconductor memory having a layout structure in which a memory cell has excellent patterning controllability. A pattern of element components (active regions 10 to 15 and 21 to 23 and polysilicon regions 31 to 42) of a memory cell for one memory cell unit of a memory cell array region 1 is identical to that of a dummy cell of a peripheral dummy cell region 3, and both patterns present a line symmetrical relationship with respect to a boundary line BC1. In addition, a pattern of the memory cell for one memory cell unit of the memory cell array region 1 is identical to that of a dummy cell of a power wiring region 2, and both patterns present a line symmetrical relationship with respect to a boundary line BC2.