摘要:
Successive data read access with a final address specified is detected by a command mode detecting circuit to set a command mode entry status. In the command mode entry, a command of designating an internal state is made acceptable in accordance with a predetermined external signal. Consequently, a semiconductor memory device that enters a command mode, maintaining compatibility of pins and signal timings with a conventional static memory is provided.
摘要:
A semiconductor memory device according to the present invention includes a memory core portion, a test mode control circuit for transmitting data output from the memory core portion to an internal node, and a data input/output control circuit for inputting/outputting in series a plurality of pieces of parallel data input/output to each internal node to a data node. The test mode control circuit transmits read data from the memory core portion as it is to the internal node in a normal reading operation, and compresses data output from the memory core portion on the basis of a prescribed unit and transmits the data to the internal node in a test mode. Therefore, the test data compressed for each prescribed unit can be input/output by using a smaller number of data nodes in the test mode than in the normal operation mode.
摘要:
Current is reduced in driving a word line in stress acceleration testing such as burn-in, and the time required for the stress acceleration testing is reduced. For an address signal applied from an address buffer, a predetermined internal address signal bit is degenerated and a remaining address signal bit is rendered valid in response to an activation of a stress acceleration mode designation signal to simultaneously drive a desired number of word lines of all word lines to selected state. Any number of word lines can be simultaneously selected and hence current flowing in driving word lines can be reduced in the stress acceleration mode. In the stress acceleration mode of operation, bit line voltage and cell plate voltage are changed, and a current required for driving a plurality of word lines into a selected state is limited.
摘要:
Conductive lines for electrostatic shielding including at least one signal line are arranged between a global data I/O bus line and a ground line transmitting a ground voltage to a nonselected word line through a sub-decoder. Capacitive coupling between bus lines included in the global data I/O bus and the ground line is suppressed, and floating up of a ground voltage on the nonselected word line is prevented.
摘要:
A memory device having a smaller circuit area but efficiently used is provided. A plurality of main word lines (MWL) extending in a row direction are connected through respective bank latches (BL) to a single global word line (GWL) extending across banks (BANK0, BANK1). Selective activation of an enable signal (BLE) and the global word line (GWL) selects one of the bank latches (BL) to selectively activate an associated main word line (MWL). This state is held by the selected bank latch (BL) after the enable signal (BLE) is inactivated. Then, another enable signal (BLE) is activated to selectively activate another main word line (MWL). Sub-decoders (SD) connected to the main word lines (MWL) are selected independently of each other to independently activate word lines (WL) for each bank (BANK).
摘要:
Memory mats provided in four regions formed by dividing a semiconductor chip are each further divided into a plurality of memory arrays along the longer side direction of the chip, row related circuits are provided between the memory arrays along the shorter side direction of the chip, and column decoders are provided along the longer side direction of the chip. An internal control signal from a master control circuit in the central part of the chip is transmitted in the central region with respect to the shorter side direction of the chip, buffer circuits are provided to an internal control signal transmission bus, and an internal signal is transmitted to the row related circuit and the column decoder by the buffer circuit. The length of the signal line to drive is shortened, and therefore the signal can be transmitted at a high speed, thus enabling high speed accessing. Thus, signal propagation delay can be reduced even if the chip size increases.
摘要:
This invention discloses a semiconductor memory device having a voltage supply circuit for generating a driver power supply voltage. The voltage supply circuit is provided with a first voltage supply circuit for precharging the driver power supply voltage to a power supply voltage level of a memory cell, and a second voltage supply circuit for supplying a voltage lower than the power supply voltage level of the memory cell as the driver power supply voltage.
摘要:
In a DRAM having a complete hidden refresh function, when data refresh is to be carried out in an active mode, a signal for selecting a way is set to an “H” level and then reset to an “L” level at each cycle while the corresponding upper address is designated. When data refresh is to be carried out in a standby mode, the signal for selecting the way is maintained at an “H” level and is not reset to an “L” level while the corresponding upper address is designated. This can reduce the standby current.
摘要:
In a DRAM having a complete hidden refresh function, when data refresh is to be carried out in an active mode, a signal for selecting a way is set to an “H” level and then reset to an “L” level at each cycle while the corresponding upper address is designated. When data refresh is to be carried out in a standby mode, the signal for selecting the way is maintained at an “H” level and is not reset to an “L” level while the corresponding upper address is designated. This can reduce the standby current.
摘要:
A composite gate detects whether an internal array is in a selected state and an internal row activation signal is activated in accordance with a timing relationship between an output signal of the composite gate and an address transition detection signal. When the address transition detection signal is applied, the internal row activation signal is deactivated in accordance with generation timings of delayed restore period signal indicating whether the internal array is in a selected state and of the address transition detection signal to permit the next row access. With such a configuration, the next operation is allowed to start after an internal state is surely restored to an initial state. When the next address transition detection signal is applied during a period of a restoration operation, a column recovery operation, or a refreshing operation, data access is correctly performed without causing data destruction.