Semiconductor memory device and testing method thereof
View Patent ↗A semiconductor memory device includes mini arrays and a serial-parallel conversion circuit. The serial-parallel conversion circuit simultaneously writes two continuous data into mutually different mini arrays out of plural data that are continuously input synchronously with an internal clock, and continuously outputs two data simultaneously read from different mini arrays, synchronously with the internal clock. In testing the semiconductor memory device according to the present invention, one data is written during a period when an external clock having a cycle of an integer times cycle of the internal clock is fixed to a high level or a low level. With this arrangement, continuous data can be assigned to mutually different mini arrays.
1. A semiconductor memory device, comprising:
a plurality of mini arrays; and
a serial-parallel conversion circuit that supplies write data to the plurality of mini arrays and outputs read data supplied from the mini arrays,
wherein said serial-parallel conversion circuit simultaneously supplies at least two continuous write data to different mini arrays that are continuously supplied from an outside synchronously with an internal clock, and continuously outputs at least two read data simultaneously supplied from different mini arrays, synchronously with the internal clock,
said internal clock has a frequency that is N (even number) times frequency of an external clock, and
M (even number: M≧N) data that are continuously input and output synchronously with the internal clock are assigned to different mini arrays, during a period when the external clock is fixed to a high level or a low level.
2. The semiconductor memory device as claimed in claim 1 , wherein said internal clock has a frequency that is two times the frequency of the external clock, and two data that are continuously input and output synchronously with the internal clock are assigned to different mini arrays, during a period when the external clock is fixed to a high level or a low level.
3. The semiconductor memory device as claimed in claim 1 , wherein said internal clock has a frequency that is four times the frequency of the external clock, and four data that are continuously input and output synchronously with the internal clock are assigned to different mini arrays, during a period when the external clock is fixed to a high level or a low level.
4. The semiconductor memory device as claimed in claim 1 , wherein said internal clock has a frequency that is four times the frequency of the external clock, and four data that are continuously input and output synchronously with the internal clock are alternately assigned to two different mini arrays, during a period when the external clock is fixed to a high level or a low level.
5. The semiconductor memory device as claimed in claim 1 , wherein said internal clock has a frequency that is eight times the frequency of the external clock, and eight data that are continuously input and output synchronously with the internal clock are assigned to different mini arrays, during a period when the external clock is fixed to a high level or a low level.
6. The semiconductor memory device as claimed in claim 1 , wherein said internal clock has a frequency that is eight times the frequency of the external clock, and out of eight data that are continuously input and output synchronously with the internal clock, four continuous data are assigned to different mini arrays, thereby assigning two data to different four mini arrays.
7. The semiconductor memory device as claimed in claim 1 , wherein said internal clock has a frequency that is four times the frequency of the external clock, and eight data that are continuously input and output synchronously with the internal clock are alternately assigned to two different mini arrays, during a period when the external clock is fixed to a high level or a low level.
8. A testing method of a semiconductor memory device having a plurality of mini arrays and serial-parallel conversion circuits provided to the respective mini arrays, each serial-parallel conversion circuit supplying write data in parallel to a corresponding mini array, and outputting read data in series which are supplied in parallel from the corresponding mini array, the testing method comprising:
a first step for supplying a plurality of write data to the respective serial-parallel conversion circuits synchronously with an internal clock in the order of receiving the write data in series so that each serial-parallel conversion circuit receives at least two write data in series;
a second step for simultaneously supplying the at least two write data in parallel from each serial-parallel conversion circuit to a corresponding mini array; and
a third step for supplying at least two read data in parallel to each serial-parallel conversion circuit from the corresponding mini array, and outputting the read data from the serial-parallel conversion circuits synchronously with the internal clock, wherein
said internal clock has a frequency that is N (even number) times frequency of an external clock, and
M (even number: M≧N) data that are continuously input and output synchronously with the internal clock are assigned to different mini arrays, during a period when the external clock is fixed to a high level or a low level.
9. A semiconductor memory device, comprising:
at least first and second mini arrays each receiving and outputting data in parallel;
a first serial-parallel conversion circuit provided to the first mini array, the first serial-parallel conversion circuit receiving first data each supplied in series every two or more cycles of an internal clock so as to supply the received first data in parallel to the first mini array, and receiving the first data from the first mini array in parallel and outputting the first data every two or more cycles of the internal clock in series; and
a second serial-parallel conversion circuit provided to the second mini array, the second serial-parallel conversion circuit receiving second data each supplied in series every two or more cycles of the internal clock alternately with those supplied to the first serial-parallel conversion circuit, so as to supply the received second data in parallel to the second mini array, and receiving second data in parallel from the second mini array and outputting the second data in series every two or more cycles of the internal clock alternately with those supplied to the first serial-parallel conversion circuit, wherein
said internal clock has a frequency that is N (even number) times frequency of an external clock, and
M (even number: M≧N) data that are continuously input and output synchronously with the internal clock are assigned to different mini arrays, during a period when the external clock is fixed to a high level or a low level.