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PRECHARGE 方式参考
1) auto-precharge is a read- or write- command with precharge.At the end of the read or write cycle, the bank will be precharged,and available t(RP) later for a bank activate command.precharge is a seperate command cycle to a particular (or all banks). A precharge command will close any open banks, and the bank(s) will then be available for activation t(RP) later. (See datasheets for t(RP)).
2) there are two-modes self-refresh and auto-refresh. Auto-refresh is similar to the old CBR (CAS before RAS) refresh, where an internal counter stores the row and column, and each is incremented on a auto-refresh cycle. self-refresh is designed to keep the contents of memory while in a owerdown type situation. The internal counters activate and perform a series of internal refresh operations. When exiting self-refresh mode, I believe you have to execute
a certain number of auto-refresh cycles, to ensure the device is fully refreshed. |
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