摘要:
In a semiconductor memory device operable in synchronism with a clock signal externally supplied thereto, there are provided a first part which detects a state of a predetermined signal after a given command is input to the semiconductor memory; and a second part which sets, on the basis of the state of the predetermined signal, the semiconductor memory device to a self-refresh mode in which a refresh operation is carried out without an external signal.
摘要:
A semiconductor memory device includes an SRAM provided on a chip, the SRAM including an SRAM cell array. A DRAM is provided on the chip, the DRAM including a DRAM cell array. An address input circuit receives an address signal, the address signal having a first portion and a second portion, the first portion carrying a unique value of row-column address information provided to access one of memory locations in one of the SRAM and DRAM cell arrays, the second portion carrying a unique value of SRAM/DRAM address information provided to select one of the SRAM and the DRAM.
摘要:
Signals supplied to predetermined terminals are accepted as commands at a plurality of times, the number of operating modes is sequentially narrowed down based on the command each time and an internal circuit is controlled according to the narrowed operating modes. Since the information necessary for determining an operating mode is accepted at a plurality of times, the number of terminals necessary for inputting commands can be reduced. In particular, in case of inputting commands at a dedicated terminal, its input pads, input circuits, or the like are no longer be required so that the chip size can be reduced. The reduction is accomplished by reducing the number of terminals, which gives limits to the package size. The command controlling circuit with a plurality of accepting circuits is comprised. Each of the accepting circuits respectively accepts signals, supplied at a plurality of times, each time. In other words, in accordance with the timing of the signal supplement, a different accepting circuit is respectively operated and the internal circuit is controlled. Accordingly, a command controlling circuit may be readily designed even in the semiconductor memory device having a complicated command combination. Consequently, it is able to facilitate the verification of the design.
摘要:
A semiconductor memory device, such as a DRAM, which needs to be refreshed for retaining data, is provided with a storing portion for storing data therein, and a busy signal outputting portion outputting a busy signal during the refresh operation.
摘要:
A semiconductor memory device includes an SRAM provided on a chip, the SRAM including an SRAM cell array. A DRAM is provided on the chip, the DRAM including a DRAM cell array. An address input circuit receives an address signal, the address signal having a first portion and a second portion, the first portion carrying a unique value of row-column address information provided to access one of memory locations in one of the SRAM and DRAM cell arrays, the second portion carrying a unique value of SRAM/DRAM address information provided to select one of the SRAM and the DRAM.
摘要:
A semiconductor memory device has a burst write mode in which predetermined plural command signals are input through a plurality of command pads and a mask control operation in the burst write mode is performed in response to the command signals. Therefore, the mask control in burst write mode is increased in speed to give an improved data transfer rate.
摘要:
A semiconductor memory device, such as a DRAM, which needs to be refreshed for retaining data, is provided with a storing portion for storing data therein, and a busy signal outputting portion outputting a busy signal during the refresh operation.
摘要:
A semiconductor memory device has a burst write mode in which predetermined plural command signals are input through a plurality of command pads and a mask control operation in the burst write mode is performed in response to the command signals. Therefore, the mask control in burst write mode is increased in speed to give an improved data transfer rate.
摘要:
A semiconductor memory device operating in synchronism with a clock includes an address latch&comparator part latching a first address signal associated with a write command and comparing the first address signal with a second address signal associated with a read command. A write data buffer part holds a data signal associated with the write command. The data signal held in the write data buffer part is read as a data signal requested by the read command when the first and second address signals coincide with each other.
摘要:
An electronic instrument includes a memory device, clock lines through which complementary clock signals are transmitted to be used for synchronization of a data output operation and a data input operation for the memory device, and strobe signal lines through which a first output strobe signal, a second output strobe signal, a first input strobe signal and a second input strobe signal are transmitted to be used to settle output data from the memory device in the data output operation and to settle input data supplied to the memory device, the first and second output strobe signals being in complementary relation to each other, the first and second input strobe signals being in complementary relation to each other.