EP0798733A2

A synchronous semiconductor memory integrated circuit, a method for accessing said memory and a system comprising such a memory

Abstract

The invention relates to a synchronous semiconductor memory integrated circuit which operates by use of edges of an external clock signal, said memory comprising a memory block; an input for an external clock signal; an address input means providing a first address as an output in response to a first edge of said external clock signal, and a second address as an output in response to a second edge of said external clock signal; access means for accessing a location in said memory block corresponding to said first address and said second address; and control means for receiving an external control input indicating a read/write mode defining a read mode and/or a write mode, and for changing said read/write mode based on a difference of level of said external control input at two successive edges of said external clock signal. Furthermore the invention relates to a method for accessing such a memory and a system comprising such a memory.

EP0798733A2, drawing sheet 1
Sheet 1 of 14

Term

Term ended

Projected expiry passed 29 November 2009, 16.8 years ago.

  1. Priority
  2. Filed
  3. Published
  4. Projected expiry
  5. Today

23 claims: 3 independent, 20 dependent

  1. 1
    A synchronous semiconductor memory integrated circuit which operates by use of edges of an external clock signal, said memory comprising:a memory block including a plurality of memory cells for storing information;an input for receiving said external clock signal;an address input means for receiving a first address and a second address, said address input means providing said first address as an output in response to a first edge of said external clock signal, said address input means providing said second address as an output in response to second edge of said external clock signal;access means for accessing a location in said memory block corresponding to said first address and said second address provided by said address input means;and control means for receiving an external control input indicating a read/write mode defining one of a read mode and a write mode, and for changing said read/write mode based on a difference of level of said external control input at two successive edges of said edges of said external clock signal.
  2. 14
    In a synchronous memory integrated circuit which operates by use of edges of an external clock signal, said memory including a memory block having a plurality of memory cells for storing information; address input means for receiving a first address and a second address; control means for receiving an external control input indicating a read/write mode defining one of a read mode and a write mode; and an input for receiving said external clock signal, a method for accessing said memory, comprising the steps of:a) providing said first address as an output of said address input means in response to a first edge of said external clock signal;b) providing said second address as an output of said address input means in response to a second edge of said external clock signal;c) accessing a location in said memory block corresponding to said first address and said second address provided by said address input means;and d) changing said read/write mode based on a difference of level of said external control input at two successive edges of said external clock signal.
  3. 16
    A system comprising a memory for operating by use of edges of a clock signal, a circuit for accessing said memory, and a bus connecting said circuit to said memory, said circuit comprising means for providing a first address and second address on said bus and means for providing a control input indicating a read/write mode defining one of a read mode and a write mode on said bus, said first address being valid on said bus on a first edge of said clock signal and said second address being valid on said bus on a second edge of said clock signal, said control input being valid on said bus on an edge of said clock signal; and said memory being a synchronous semiconductor memory integrated circuit comprising:a memory block including a plurality of memory cells for storing information;an input for receiving said clock signal;address input means for receiving said first address and said second address through said bus, said address input means providing said first address as an output in response to said first edge of said clock signal, said address input means providing said second address as an output in response to said second edge of said clock signal;access means for accessing a location in said memory block corresponding to said first address and said second address provided by said address input means;and control means for receiving said control input through said bus, and for changing said read/write mode based on a difference of level of said control input at two successive edges of said edges of said clock signal.