Re: [理工] 計算機組織與系統

看板Grad-ProbAsk作者BF3716 (JS)時間16年前 (2009/04/17 16:50)推噓3(3推 0噓 4→)

留言7則, 5人參與討論串2/2 (看更多)

We want to compare the maximum bandwidth for a synchronous and asynchronous bus. The synchronous bus has a clock cycle time of 50ns,and each bus transmission takes 1 clock.The asynchronous bus requires 40 ns per handshake.The data portion of both buses is 32 bits wide.Find the bandwidth for each bus when performing one-word reads from a 220-ns memory. [同步] 1. 傳送位址給記憶體: 50ns 2. 記憶體存取: 220ns 3. 傳送資料: 50ns 傳送one-word 合計需要320ns one-word 4bytes 匯流排頻寬: ---------- = --------- = 12.5 MB/Sec 320ns 320ns [非同步] 交握協定具有7個step 1. step1 : 40ns 2. step234 : max(3*40ns,220ns) = 220ns 3. step5 : 40ns 4. step6 : 40ns 5. step7 : 40ns 傳送one-word 合計需要380ns one-word 4bytes 匯流排頻寬: ---------- = --------- = 10.52 MB/Sec 380ns 380ns -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 211.74.186.222

推

sak1346

04/17 16:52, , 1^F

04/17 16:52, 1^F

推

newfantasy

04/17 17:08, , 2^F

04/17 17:08, 2^F

推

beautyanzi

04/17 21:24, , 3^F

04/17 21:24, 3^F