Supporting scan functions within memories

A method of providing a scan function to a memory, said memory comprising:

• a storage array for storing data;
• and
• access circuitry for transmitting said data to and from said storage array, said access circuitry forming a data path for inputting and outputting data to said storage array;
• said access circuitry comprising a latch configured to latch in response to a first phase of a first clock signal and a further latch configured to latch in response to a second phase of a second clock signal, said further latch comprising an output latch for outputting said data from said storage array, and said first and second clock signals are synchronised with each other;
• said method comprising the steps of:
• providing a multiplexer, said multiplexer having a scan input a data input, said multiplexer selecting between said scan input and data input in response to a scan enable signal;
• inputting said scan enable signal to said multiplexer;
• in response to said scan enable signal forming a scan path comprising said latch and said further latch connected together to form a master slave flip flop;
• inputting scan data at said scan input and transmitting said input scan data through said master slave flip flop and not through said storage array.

A data storage means comprising:

• a storage array means for storing data;
• and
• access means for transmitting said data to and from said storage array means, said access means forming a data path for inputting and outputting data to said storage array means, said access means comprising a latching means for latching in response to a first phase of a first clock signal and a further latching means for latching in response to a second phase of a second clock signal, said further latching means comprising an output latching means for outputting said data from said storage array means, and said first and second clock signals are synchronised with each other;
• said data storage means further comprising:
• a multiplexing means, a scan input means and a scan enable input means, said multiplexing means being responsive to an asserted scan enable signal at said scan enable input to form a scan path comprising said latching means and said further latching means connected together to form a master slave flip flop means, such that scan data input at said scan input passes through said master slave flip flop means and not through said storage array means while said scan enable signal is asserted and is output by said output latching means.