Claims
- 1. A semiconductor memory device comprising:
- a memory cell array;
- a read circuit which reads data from said memory cell array;
- an external terminal which receives an external clock signal;
- a first input circuit which receives the external clock signal therein and outputs a first internal clock signal delayed from the external clock signal;
- a second input circuit which receives the first internal clock signal therein and outputs a second internal clock signal delayed from the first internal clock signal;
- a circuit which counts a clock signal having a frequency higher than that of the external clock signal;
- a circuit which starts said counting in response to the second internal clock signal, reverses the direction of said counting in response to the first internal clock signal and detects when a count of said counting circuit again reaches the count at the start of said counting, thereby outputting a timing signal therefrom; and
- a clock output circuit which outputs a third internal clock signal for controlling the operation of said read circuit based on the timing signal.
- 2. A semiconductor memory device according to claim 1, further comprising:
- a circuit which produces a clock signal having a frequency higher than that of said external clock signal.
- 3. A semiconductor memory device according to claim 1, wherein said timing signal is produced so that rise timing of the external clock signal coincides with that of the third internal clock signal.
- 4. A semiconductor memory device according to claim 1, wherein a delay time corresponding to said second input circuit is set so as to correspond to the sum of a delay time corresponding to said first input circuit and a delay time corresponding to said clock output circuit.
Priority Claims (1)
Number |
Date |
Country |
Kind |
8-314225 |
Nov 1996 |
JPX |
|
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of application Ser. No. 08/967,612, filed on Nov. 10, 1997, now U.S. Pat. No. 5,955,905, the entire disclosure of which is hereby incorporated by reference.
US Referenced Citations (9)
Non-Patent Literature Citations (1)
Entry |
T. Saeki et al., "SP 23.4: A 2.5 ns Clock Access 250 MHz 256Mb SDRAM with a Synchronous Mirror Delay", 1996 IEEE Int'l Solid-State Circuits Conference, Session 23/DRAM/Paper SP23.4. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
967612 |
Nov 1997 |
|