作者future1234 (Creep)
看板TransCSI
标题Re: [问题] 关於中兴95年计概转学考考题
时间Mon Jun 23 23:20:25 2008
※ 引述《hothero (hothero)》之铭言：
: (a)A single board computer has four data register (R0 to R3),1024 words
: in memory,and 16 different instructions (Add,Subtract,Load,etc.),and the
: length of a program is limited within 512 lines.What is the minimum size of
: an instruction in bits if a typical instruction uses the format:Load [123] R1,
: which means to load the data at the address 123 to register R1.
Instruction Format:
op rd address
0000 00 00.....00
op:opcode , 可以做16个运算 , 4个bit去表示
rd:register destination operand, 在这R0 to R3 ,2个bit
address:假设1个 word= 8 bytes=64 bits , 1024 words就总共2^16 , 16个bit
所以指令长度是 4+2+16= 22 bits
: (b)If the computer uses the same size of word for data and instructions,
: what is the size of each data register?
Pentium架构的cpu:
一个word=64 bits
: (c)What is the size of the program counter in bits?
64 bits
: (d)What is the size of the address bus?
36 bits (Addressable 64G)
(e)What is the size of the control bus?
I don't know.
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 203.67.210.63
1F：推 hothero:我有问题，(a)为什麽假设1word=8bytes不是1byte阿?? 06/30 20:06
2F：→ hothero:(b)是怎麽知道他是pentium的cpu阿?? 06/30 20:07
3F：→ hothero:(c)program counter的大小是参考位址线还是资料线呢?? 06/30 20:08
4F：→ hothero:(D)为什麽(A)的address是16bits，这变成36bits了?? 06/30 20:08
5F：→ hothero:sorry，问题有点多>"<~谢谢 06/30 20:09
6F：→ future1234:你怎现在才问= = 06/30 20:11
7F：推 hothero:呵呵，因为问很久了...刚刚才发现>"< 06/30 20:40