1 Reply Latest reply on Feb 14, 2019 2:05 AM by PradiptaB_11

    Need support to know technical meaning


      We need your support to know the definition of these expressions

      1- Sleep Mode option and Stop Clock option

      2-Automatic power down

      3-On-Die Termination (ODT)

      4- Full data coherency

      5- Fully asynchronous operation

      6-RadStop™ Technology

        • 1. Re: Need support to know technical meaning

          Hi Sameh,


          Please find my comments below.


          1) Sleep Mode : The devices which have a sleep mode option can utilize this mode. During sleep mode the device will consume minimal current usually in micro Amperes and hence dissipate the least power possible for the device, thus prolonging the life of the power source. Usually such ICs are preferred for very low power application where battery life is one of the most important design considerations. 


          Stop Clock : In Sync SRAMs all the operations are governed/controlled via the clock. Inputs/Outputs, all the control signals are latched onto the device on rising/falling edges of the clock. If the clock is discontinued after some time the device enters into a standby mode and will maintain its previous state as long as a clock is provided with appropriate control signals. Please note while the clock is discontinued any changes in the other control signals like Address pins will not have any impact on the device.


          2) Automatic Power Down : Say, take an example of QDR II+ memories. It has two independent ports one for read and other for write. If at any point during the operation if both the ports are deselected the device will be taken automatically into standby mode where the current consumption will be less  660 mA instead of 1700 mA which is the active mode current. Please note values used are maximum values from the datasheet. It prolongs the life of the battery/power source.


          3) ODT : High frequency signals are susceptible to losses along transmission lines thereby causing signal distortion at the receiver. This will impact the receiver’s ability to interpret information correctly. In order for a transmission line to minimize distortion of the signal, the impedance of every location on the transmission line should be uniform throughout its length. If there is any place in the line where the impedance is not uniform for some reason (open circuit, impedance discontinuity, different material) the signal gets modified by reflection at the impedance change point which results in distortion, ringing and so forth. When the signal path has impedance discontinuity, in other words an impedance mismatch, then termination impedance with the equivalent amount of impedance is placed at the point of line discontinuity.

          There are different methods of termination.

           Using external resistors – Attach an external resistor with a suitable resistance value at the end of the transmission line.

           On-die termination (ODT) – Embed the termination resistors within the die.


          Please refer to the application note below for more information.



          4) Full data Coherency : The read and write ports on the device  operate independently of one another. As each port latches the address inputs on different clock edges, you can read or write to any location, regardless of the transaction on the other port. You can start reads and writes in the same clock cycle. If the ports access the same location at the same time, the SRAM delivers the most recent information associated with the specified address location. This includes forwarding data from a write cycle that was initiated on the previous K clock rise.


          5) Fully asynchronous operation : In general asynchronous operation implies that no clock is there to govern/ control the device operation. So the device can operate without any sync to any clock. Any changes in the control signals will be latched to the device immediately and have a corresponding result.


          6) RadStop Technology : The single event latch up (SEL) immunity is improved by a radiation hardened design technique developed by Cypress called RadStop. This design mitigation technique allows the SEL performance to achieve radiation hard performance levels. Please refer to the datasheet of any rad tolerant device to see the rad performance of the device. We also have an app note on this for more information.




          Thanks and Regards,