5 results about "Static random-access memory" patented technology

The invention relates to a starting method of satellite borne software. The method comprises the following steps: ground compression software stores an object code of the satellite borne software in a programmable read only memory (PROM) after multiple lossless compression; and after a satellite computer is electrified or reset, a starting program decompresses and reduces compression data of the satellite borne software stored in the PROM to a static random access memory (SRAM) and operates. The memory efficiency of the PROm is effectively improved, the flight program and the starting program which are normally cured in the PROM are realized, so that the space cost and the maintenance cost brought by redundant backup are lowered, the safety of the satellite is extremely improved, the PROM is not overturned by single particles, EEPROM is not dependent, on-orbit maintenance times in the later stage can be greatly reduced, and the fault-tolerant ability of operation of the satellite borne computer is enhanced.

The invention relates to a non-contact synchronous measuring instrument for subgrade and rail vibration. A CCD (Charge Coupled Device) drive circuit is respectively connected with a CCD video signal binaryzation processing unit, an A / D and SRAM (Static Random Access Memory) working time sequence controller and an address counter time sequence generator and used for providing a necessary working pulse for a CCD and generating an interface signal between the CCD drive circuit and a data acquisition card; and the output of the CCD video signal binaryzation processing unit and the outputs of the A / D and SRAM working time sequence controller and the address counter time sequence generator are connected with a data acquisition interface circuit based on a parallel interface. By computer control automatic measurement, the invention greatly prevents the influence of human factors, realizes the intellectualization of detection, solves the synchronous problem of two different vibration frequencies and vibration amplitudes by non-contact synchronous measurement and can carry out software calibration at random, thereby preventing precision reduction caused by long-term use. A photoelectric probe is just dedusted regularly without replacing a detecting probe regularly.