Memory design
AssigneeCambridge Silicon Radio Limited
InventorsPaul Egan, Simon Chang
Life of this patent
Estimating the term…
Abstract
A SRAM memory element comprises an influencing element which sets the state of the memory cells within the memory element on start-up to defined values. These defined values are set at the design stage such that on start-up the volatile memory contains firmware or other data. Dependent upon the implementation of the influencing element, the values of stored in the memory cells may be fixed or may subsequently be overwritten during operation of the device. The memory cell may comprise two cross-coupled inverters and the influencing element comprises at least one transistor arranged to connect the input to one of the inverters to ground or a power supply rail when voltage is applied to a controlling node of the transistor.
Claims13
A static RAM memory element comprising:
- a plurality of RAM memory cells;
- and at least one influencing element arranged to set a state of at least a subset of the RAM memory cells to a specified value on start-up so that on start-up the subset of the RAM memory cells contains program code without copying data to the subset of RAM memory cells from another memory location.
A method of fabricating a static RAM memory element comprising:
- forming a plurality of RAM memory cells and at least one influencing element arranged to set a state of at least a subset of the RAM memory cells to a specified value on start-up so that on start-up the subset of the RAM memory cells contains program code without copying data to the subset of RAM memory cells from another memory location;
- and selecting and using a mask layer arranged to define the state of a least the subset of the RAM memory cells by forming electrical connections between nodes in the subset of RAM memory cells and a power rail.
Dependencies are inferred from the claim text.