Chapter4 homework
一、Select the best answer based on this couese ( 选择题 ). 1. The computer memory system refers to _________
A.RAM B. ROM C. Main memory D.Register , main memory, cache, external memory 2. If the word of memory is 16 bits, which the following answer is right?
A. The address width is 16 bits B. The address width is related with 16 bits C.The address width is not related with 16 bits D. The address width is not less than 16 bits 3. The characteristics of internal memory compared to external memory
A. Big capacity, high speed, low cost B. Big capacity, low speed, high cost C. small capacity, high speed, high cost D. small capacity, high speed, low cost 4．On address mapping of cache, any block of main memory can be mapped to any line of cache, it is ___________ .
A. Associative Mapping B. Direct Mapping C. Set Associative Mapping D. Random Mapping 5. Cache’s write-through polity means write operation to main memory _______.
A. as well as to cache B. only when the cache is replaced C. when the difference between cache and main memory is found D. only when direct mapping is used 6. Cache’s write-back polity means write operation to main memory ______________.
A. as well as to cache B. only when the relative cache is replaced C. when the difference between cache and main memory is found D. only when using direct mapping
7. On address mapping of cache, the data in any block of main memory can be mapped to fixed line of cache, it is _________________.
A. associative mapping B. direct mapping C. set associative mapping D. random mapping
8. On address mapping of cache, the data in any block of main memory can be mapped to fixed set any line(way) of cache, it is _________________.
A. associative mapping B. direct mapping C. set associative mapping D. random mapping 9. Computer memory is organized into a hierarchy. At the highest level are the ___________.
A. registers B. cache C. main memory D. external memory
10. On address mapping of cache, the data in any block of main memory can be mapped to __________ of cache, it is direct mapping .
A. any line B. fixed line C. fixed set any line D. A and B
11. The characteristics of external memory compared to internal memory are _______ . A.Big capacity, high speed, low cost B. Big capacity, low speed, low cost C. small capacity, high speed, high cost D. small capacity, high speed, low cost 12. Write _____ policy can result in memory write bottle-neck. A. back B. through C. from D. to
13.A 16KByte cache has a line size of four 32-bit words, the number of line is . A 210 B 10 C 28 D 8
14. If the address-length of memory is 16 bits, which the following answer is NOT right ? . A.The addressable unit is 16 bits B.The addressing range is 216
C.The maxmum possible memory capacity is determined D.The addressable unit is not related with 16 bits
15. Suppose that the word from location X in memory can be mapped any line in the cache, this mapping function is called _____________.
A. associative Mapping B. direct Mapping C. set Associative Mapping D. random Mapping
16. The simplest technique is called _____________.Using this technique, all write operations are made to main memory as well as to the cache.
A. write-back B. write-through C. write-invalidate D. write-update
二：计算题(第八版第146 页 第六版第126页)
Problems： 4.1，4.2，4.3 ，4.4 ，4.5 ，4.6 ，4.8， 4.11
（ 提示：为了更好理解4.5和4.6两题的题意，做了适当修改（单位统一），先做修改后的，再做书上）
Problem 4.5: Consider a 32-bit microprocessor that has an on-chip 4Kwords four way set associative cache. Assume that the
cache has a line size of four words.
a. Show the mapping format of address.
b. How the different address fields are used to determine a cache hit/miss?
c. Where in the cache is the word from memory location ABCDE8F8 mapped?
Problem 4.6 : Given the following specifications for an external cache memory: four-way set associative ; line size of two
words; able to accommodate a total of 8Kwords from main memory; used with a 16-bit processor that issues 24-bit addresses. Show the mapping format of address.
第4章 作业
