23 CAR § 355-1349. Critical memory integrity

(a) Comprehensive checks of critical memory shall be made during each EGS restart (e.g., power-up cycle). (b)(1) The EGS control program shall be continuously monitored for possible corruption of critical memory. (2) In addition, it is recommended that a trip redundancy check be implemented. (c) Test methodology shall detect ninety-nine and ninety-nine hundredths percent (99.99%) of all possible failures. (d) In addition, all critical memory (nonvolitile) shall: (1)(A) Have the ability to retain data for a minimum of thirty (30) days after power is discontinued from the machine. (B) If the method used is an off chip battery source, it shall recharge itself to its full potential in a maximum of twenty-four (24) hours. (C) The shelf life shall be at least five (5) years. (D) Random access memory that uses an off-chip back-up power source to retain its contents when the main’s power is switched off shall have a detection system which will provide a method for software to interpret and act upon a low battery condition; (2) Only be cleared by accessing the locked logic area in which it’s housed; (3) Result in a RAM error if the control program detects an unrecoverable memory error; and (4) The RAM should not be cleared automatically, but shall require a full RAM clear (RAM reset) performed by an authorized person.