å
åæ¶åº ä¸ç§åæ°ï¼ä¸è¬åå¨å¨å
åæ¡çSPDä¸ã2-2-2-8 4个æ°åçå«ä¹ä¾æ¬¡ä¸ºï¼CAS Latencyï¼ç®ç§°CLå¼ï¼å
åCAS延è¿æ¶é´ï¼æ¯å
åçéè¦åæ°ä¹ä¸ï¼æäºçåçå
åä¼æCLå¼å°å¨å
åæ¡çæ ç¾ä¸ãRASï¼toï¼CAS Delayï¼tRCDï¼ï¼å
åè¡å°åä¼ è¾å°åå°åç延è¿æ¶é´ãRowï¼precharge Delayï¼tRPï¼ï¼å
åè¡å°åééèå²é¢å
çµæ¶é´ãRowï¼active Delayï¼tRASï¼ï¼å
åè¡å°åéé延è¿ã
该åæ°å¯¹å
åæ§è½çå½±åæ大ï¼å¨ä¿è¯ç³»ç»ç¨³å®æ§çåæä¸ï¼CASå¼è¶ä½ï¼åä¼å¯¼è´æ´å¿«çå
å读åæä½ãCLå¼ä¸º2为ä¼è·å¾æä½³çæ§è½ï¼èCLå¼ä¸º3å¯ä»¥æé«ç³»ç»ç稳å®æ§ã注æï¼WinbondBH-5/6è¯çå¯è½æ æ³è®¾ä¸º3ã
RAS# to CAS# Delay(tRCD)
å¯éç设置ï¼Autoï¼0ï¼1ï¼2ï¼3ï¼4ï¼5ï¼6ï¼7ã
该å¼å°±æ¯â3-4-4-8âå
åæ¶åºåæ°ä¸ç第2个åæ°ï¼å³ç¬¬1个4ãRAS# to CAS# Delay(ä¹è¢«æ述为ï¼tRCDãRAS to CAS DelayãActive to CMD)ï¼è¡¨ç¤º"è¡å¯»åå°å寻å延è¿æ¶é´"ï¼æ°å¼è¶å°ï¼æ§è½è¶å¥½ã对å
åè¿è¡è¯»ãåæå·æ°æä½æ¶ï¼éè¦å¨è¿ä¸¤ç§èå²ä¿¡å·ä¹é´æå
¥å»¶è¿æ¶éå¨æãå¨JEDECè§èä¸ï¼å®æ¯æå¨ç¬¬äºçåæ°ï¼éä½æ¤å»¶æ¶ï¼å¯ä»¥æé«ç³»ç»æ§è½ã建议该å¼è®¾ç½®ä¸º3æ2ï¼ä½å¦æ该å¼è®¾ç½®å¤ªä½ï¼åæ ·ä¼å¯¼è´ç³»ç»ä¸ç¨³å®ã该å¼ä¸º4æ¶ï¼ç³»ç»å°å¤äºæ稳å®çç¶æï¼è该å¼ä¸º5ï¼å太ä¿å®ã
å¦æçå
åçè¶
é¢æ§è½ä¸ä½³ï¼åå¯å°æ¤å¼è®¾ä¸ºå
åçé»è®¤å¼æå°è¯æé«tRCDå¼ã
Min RAS# Active Timing(tRAS)
å¯éç设置ï¼Autoï¼00ï¼01ï¼02ï¼03ï¼04ï¼05ï¼06ï¼07ï¼08ï¼09ï¼10ï¼11ï¼12ï¼13ï¼14ï¼15ã
该å¼å°±æ¯è¯¥å¼å°±æ¯â3-4-4-8âå
åæ¶åºåæ°ä¸çæåä¸ä¸ªåæ°ï¼å³8ãMin RAS# Active Time (ä¹è¢«æ述为ï¼tRASãActive to Precharge DelayãRow Active TimeãPrecharge Wait StateãRow Active DelayãRow Precharge DelayãRAS Active Time)ï¼è¡¨ç¤ºâå
åè¡ææè³é¢å
çµçæçå¨æâï¼è°æ´è¿ä¸ªåæ°éè¦ç»åå
·ä½æ
åµèå®ï¼ä¸è¬æ好设å¨5ï¼10ä¹é´ãè¿ä¸ªåæ°è¦æ ¹æ®å®é
æ
åµèå®ï¼å¹¶ä¸æ¯è¯´è¶å¤§æè¶å°å°±è¶å¥½ã
å¦ætRASçå¨æ太é¿ï¼ç³»ç»ä¼å 为æ è°ççå¾
èéä½æ§è½ãéä½tRASå¨æï¼åä¼å¯¼è´å·²è¢«æ¿æ´»çè¡å°åä¼æ´æ©çè¿å
¥éæ¿æ´»ç¶æãå¦ætRASçå¨æ太çï¼åå¯è½å 缺ä¹è¶³å¤çæ¶é´èæ æ³å®ææ°æ®ççªåä¼ è¾ï¼è¿æ ·ä¼å¼å丢失æ°æ®ææåæ°æ®ã该å¼ä¸è¬è®¾å®ä¸ºCAS latency + tRCD + 2个æ¶éå¨æãå¦æçCAS latencyçå¼ä¸º2ï¼tRCDçå¼ä¸º3ï¼åæä½³çtRASå¼åºè¯¥è®¾ç½®ä¸º7个æ¶éå¨æã为æé«ç³»ç»æ§è½ï¼åºå°½å¯è½éä½tRASçå¼ï¼ä½å¦æåçå
åé误æç³»ç»æ»æºï¼ååºè¯¥å¢å¤§tRASçå¼ã
å¦æ使ç¨DFIç主æ¿ï¼åtRASå¼å»ºè®®ä½¿ç¨00ï¼æè
5-10ä¹é´çå¼ã
Row Precharge Timing(tRP)
å¯éç设置ï¼Autoï¼0ï¼1ï¼2ï¼3ï¼4ï¼5ï¼6ï¼7ã
该å¼å°±æ¯â3-4-4-8âå
åæ¶åºåæ°ä¸ç第3个åæ°ï¼å³ç¬¬2个4ãRow Precharge Timing (ä¹è¢«æ述为ï¼tRPãRAS PrechargeãPrecharge to active)ï¼è¡¨ç¤º"å
åè¡å°åæ§å¶å¨é¢å
çµæ¶é´"ï¼é¢å
çµåæ°è¶å°åå
å读åé度就è¶å¿«ã
tRPç¨æ¥è®¾å®å¨å¦ä¸è¡è½è¢«æ¿æ´»ä¹åï¼RASéè¦çå
çµæ¶é´ãtRPåæ°è®¾ç½®å¤ªé¿ä¼å¯¼è´ææçè¡æ¿æ´»å»¶è¿è¿é¿ï¼è®¾ä¸º2å¯ä»¥åå°é¢å
çµæ¶é´ï¼ä»èæ´å¿«å°æ¿æ´»ä¸ä¸è¡ãç¶èï¼æ³è¦ætRP设为2对大å¤æ°å
åé½æ¯ä¸ªå¾é«çè¦æ±ï¼å¯è½ä¼é æè¡æ¿æ´»ä¹åçæ°æ®ä¸¢å¤±ï¼å
åæ§å¶å¨ä¸è½é¡ºå©å°å®æ读åæä½ã对äºæ¡é¢è®¡ç®æºæ¥è¯´ï¼æ¨èé¢å
çµåæ°çå¼è®¾å®ä¸º2个æ¶éå¨æï¼è¿æ¯æä½³ç设置ãå¦ææ¯æ¤å¼ä½ï¼åä¼å 为æ¯æ¬¡æ¿æ´»ç¸é»ç´§æ¥ççbankå°éè¦1个æ¶éå¨æï¼è¿å°å½±åDDRå
åç读åæ§è½ï¼ä»èéä½æ§è½ãåªæå¨tRPå¼ä¸º2èåºç°ç³»ç»ä¸ç¨³å®çæ
åµä¸ï¼å°æ¤å¼è®¾å®ä¸º3个æ¶éå¨æã
å¦æ使ç¨DFIç主æ¿ï¼åtRPå¼å»ºè®®2-5ä¹é´çå¼ãå¼ä¸º2å°è·åæé«çæ§è½ï¼è¯¥å¼ä¸º4å°å¨è¶
é¢æ¶è·åæä½³ç稳å®æ§ï¼åæ ·çè该å¼ä¸º5ï¼å太ä¿å®ã大é¨åå
åé½æ æ³ä½¿ç¨2çå¼ï¼éè¦è¶
é¢æå¯ä»¥è¾¾å°è¯¥åæ°ã
Row Cycle Time(tRC)
å¯éç设置ï¼Autoï¼7-22ï¼æ¥å¹
å¼1ã
Row Cycle Time(tRCãRC)ï¼è¡¨ç¤ºâSDRAMè¡å¨ææ¶é´âï¼å®æ¯å
æ¬è¡åå
é¢å
çµå°æ¿æ´»å¨å
çæ´ä¸ªè¿ç¨æéè¦çæå°çæ¶éå¨ææ°ã
å
¶è®¡ç®å
¬å¼æ¯ï¼row cycle time (tRC) = minimum row active time(tRAS) + row precharge time(tRP)ãå æ¤ï¼è®¾ç½®è¯¥åæ°ä¹åï¼åºè¯¥æç½çtRASå¼åtRPå¼æ¯å¤å°ãå¦ætRCçæ¶é´è¿é¿ï¼ä¼å å¨å®ææ´ä¸ªæ¶éå¨æåæ¿æ´»æ°çå°åèçå¾
æ è°ç延æ¶ï¼èéä½æ§è½ãç¶åä¸æ¦è¯¥å¼è®¾ç½®è¿å°ï¼å¨è¢«æ¿æ´»çè¡åå
被å
åå
çµä¹åï¼æ°çå¨æå°±å¯ä»¥è¢«åå§åã
Write Recovery Time (tWD)ï¼è¡¨ç¤ºâåæ¢å¤å»¶æ¶âã该å¼è¯´æå¨ä¸ä¸ªæ¿æ´»çbankä¸å®æææçåæä½åé¢å
çµåï¼å¿
é¡»çå¾
å¤å°ä¸ªæ¶éå¨æãè¿æ®µå¿
é¡»çæ¶éå¨æç¨æ¥ç¡®ä¿å¨é¢å
çµåçåï¼åç¼å²ä¸çæ°æ®å¯ä»¥è¢«åè¿å
ååå
ä¸ãåæ ·çï¼è¿ä½çtWDè½ç¶æé«äºç³»ç»æ§è½ï¼ä½å¯è½å¯¼è´æ°æ®è¿æªè¢«æ£ç¡®åå
¥å°å
ååå
ä¸ï¼å°±åçäºé¢å
çµæä½ï¼ä¼å¯¼è´æ°æ®ç丢失åæåã
温馨提示:答案为网友推荐,仅供参考