Other

Hitachi, Ltd.

Renesas Technology Corp.

Hitachi Ulsi Systems Co., Ltd.

Hitachi Device Engineering Co., Ltd.

Kaname Yamasaki

Hiroaki Nambu

Kazuo Kanetani

Takeshi Kusunoki

Fumihiko Arakawa

Keiichi Higeta

Makoto Hanawa

Noboru Masuda

Kenji Kaneko

Kunihiko Yamaguchi

Tatsuya Saito

Kenichi Ohhata

Iwao Suzuki

Yoshio Takamine

Keiichi Horie

Takeshi Bingo

The test design cost of a circuit capable of accessing an external memory is reduced. There is included a built-in self-test circuit for use in testing an external memory separately from a memory controller for performing memory control in response to an access request to the external memory capable of being coupled to a memory interface, and a TAP controller is used to control the built-in self-test circuit and referring to a test result. There is adopted a multiplexer for switchably selecting the memory controller or the built-in self-test circuit as a circuit for coupling to the memory interface in accordance with control information externally inputted through the TAP controller. The built-in self-test circuit programmably generates and outputs a pattern for a memory test in accordance with an instruction inputted through the TAP controller, and compares data read from the external memory with an expected value.

Semiconductor device and data processing system

Test functions are expanded by adopting a self test part, and circuit scale is reduced by adding the self test part. A semiconductor integrated circuit includes a memory that includes plural memory banks and is accessed by specifying a bank address, an X address, and a Y address, and a self-test part that tests the memory in response to commands. The self-test part has an address counter covering plural addressing modes that are different in the updating of X addresses, Y addresses, and bank addresses. A variety of addressing modes provided expand BIST-based test functions.

Semiconductor integrated circuit

To speed up the operation of a decoder circuit, reduce the power consumption of the decoder circuit and increase the cycle, each circuit such as a buffer, a predecoder and a main decoder in the decoder circuit includes a semiconductor logic circuit in which the number of columns of transistors for pulling down at an output node is small, even if the number of inputs is many and the true and a complementary output signal having approximately the same delay time are acquired and the output pulse length of each circuit in the decoder circuit is reduced. With this arrangement, the operation of the decoder circuit can be sped up, the power consumption can be reduced, the cycles can be increased and, in a semiconductor memory, for example, access time and power consumption can be reduced and the cycles can be increased.

Semiconductor integrated circuit and semiconductor logic circuit used in the integrated circuit

In a dynamic-type semiconductor integrated circuit in which precharge and evaluation operations are preformed per cycle, an IDDQ test and a light detection test can be conducted during an evaluation period for facilitating diagnosis and failure analysis so as to increase test accuracy. The dynamic-type semiconductor integrated circuit operates in a normal operation mode or a test mode, wherein a switch therebetween is triggered by a mode selection signal. In the normal operation mode, the pulse width of an internal activation signal is controlled to be constant, i.e., invariable with an operation cycle time length. In the test mode, the pulse width of the internal activation signal is controlled to vary according to an operation cycle time length.

Method of testing a semiconductor integrated device

A clocked logic gate circuit is constituted so that a switch unit is constituted by a logic block and a reference MOS transistor, the source of the reference MOS transistor is connected to one output of the logic block, the gate of the reference MOS transistor is connected to the other output of the logic block, and MOS transistors (input transistors) constituting the logic block are connected in parallel. With this arrangement, complementary inputs are not required and a driving MOS transistor and an input transistor (or a driving MOS transistor and a reference MOS transistor) can be connected in series. As a result, a circuit is obtained which is simpler than the double rail logic in constitution is facilitated and can be operated at a higher speed than a CMOS logic circuit and a path transistor logic circuit.

Clocked logic gate circuit

A transmission circuit for transmitting a data signal between circuit units through a signal wire. The data signal is transmitted for precharging the signal wire to high potential during a precharge period and discharging it to low potential according to data transmitted during an evaluation period or keeping the signal wire as it is. Latch type Source-Coupled-Logic is configured so that a first node and a second node used as an output terminal to the next stage are respectively charged together to high potential during the precharge period. The second node is discharged according to a potential at the first node during the evaluation period, and the first node is discharged according to a potential on the signal wire. Thus, the operation of discharging the signal wire by the driver circuit can be sped up.

Signal transmission circuit and semiconductor memory using the same

To speed up the operation of a decoder circuit, reduce the power consumption of the decoder circuit and increase the cycle, each circuit such as a buffer, a predecoder and a main decoder in the decoder circuit include a semiconductor logic circuit wherein the number of columns of transistors for pulling down an output node is small even if the number of inputs is large, and the true output signal and a complementary output signal having approximately the same delay time are acquired and the output pulse length of each circuit in the decoder circuit is reduced. By virtue of this arrangement, the operation of the decoder circuit can be sped up, the power consumption can be reduced, the cycles can be increased and, in a semiconductor memory, for example, the reduction of access time and power consumption and the increase of the cycles are enabled.

A transmission circuit for transmitting a data signal between circuit units through a signal wire. The data signal is transmitted for precharging the signal wire to high potential during a precharge period and discharging it to low potential according to data transmitted during an evaluation period or keeping the signal wire as it is. Latch type Source-Coupled-Logic as configured so that a first node and a second node used as an output terminal to the next stage are respectively charged together to high potential during the precharge period. The second node is discharged according to potential at the first node during the evaluation period, and the first node is discharged according to a potential on the signal wire. Thus, the operation of discharging the signal wire by the driver circuit can be sped up.

Disclosed herein is a transmission circuit for transmitting a data signal between circuit units on a semiconductor integrated circuit through a signal wire. The data signal is transmitted by a driver circuit for precharging the signal wire to a high potential during a precharge period and discharging the signal wire to a low potential according to data to be transmitted during an evaluation period or keeping the signal wire at a high potential as floating as it is. Latch type Source-Coupled-Logic configured so that a first node and a second node used as an output terminal to the next stage are respectively charged together to a high potential during the precharge period, the second node is discharged according to a potential at the first node during the evaluation period, and the first node is discharged according to a potential on the signal wire, is used as a receiving circuit, whereby a distinction as to a high or low level of the potential on the signal wire is made with early timing provided to perform the operation of discharging the signal wire by the driver circuit.

One of the factors determining cycle time of an SRAM is recovery time of a bit line after writing. When the size of a precharge PMOS transistor is increased to shorten the recovery time, delay time which is caused by making the precharge PMOS transistors non-conductive at the time of read operation, that is, access time increases. To avoid this, a semiconductor memory is provided with a second precharge circuit in addition to the conventional bit line precharge circuit. The second precharge circuit operates upon detection of completion of writing and stops operation when it detects that the bit line is precharged to a high potential. Consequently, the recovery time after write operation is shortened and the cycle time is reduced without increasing the access time.

Semiconductor memory

A semiconductor memory in accordance with the present invention includes a sense amplifier composed of a plurality of MOS transistors. When the sense amplifier is on standby, a first control circuit brings an input signal of the sense amplifier to zero. A second control circuit uses voltages developed because of an offset voltage occurring in the sense amplifier to feed back the potentials in the wells of the MOS transistors so that the offset voltage will be nullified. When the offset voltage occurring in the sense amplifier is nullified, a delay time required by the sense amplifier is shortened. This results in the high-speed semiconductor memory.

Growing community of inventors

Kokubunji, Japan

Kaname Yamasaki