• <ins id="pjuwb"></ins>
    <blockquote id="pjuwb"><pre id="pjuwb"></pre></blockquote>
    <noscript id="pjuwb"></noscript>
          <sup id="pjuwb"><pre id="pjuwb"></pre></sup>
            <dd id="pjuwb"></dd>
            <abbr id="pjuwb"></abbr>
            posts - 195,  comments - 30,  trackbacks - 0
            You are to write an interpreter for a simple computer. This computer uses a processor with a small number of machine instructions. Furthermore, it is equipped with 32 byte of memory, one 8-bit accumulator (accu) and a 5-bit program counter (pc). The memory contains data as well as code, which is the usual von Neumann architecture.

            The program counter holds the address of the instruction to be executed next. Each instruction has a length of 1 byte - the highest 3 bits define the type of instruction and the lowest 5 bits define an optional operand which is always a memory address (xxxxx). For instructions that don't need an operand the lowest 5 bits have no meaning (-----). Here is a list of the machine instructions and their semantics:

            000xxxxx   STA x   store the value of the accu into memory byte x
            001xxxxx   LDA x   load the value of memory byte x into the accu
            010xxxxx   BEQ x   if the value of the accu is 0 load the value x into the pc
            011-----   NOP     no operation
            100-----   DEC     subtract 1 from the accu
            101-----   INC     add 1 to the accu
            110xxxxx   JMP x   load the value x into the pc
            111-----   HLT     terminate program

            In the beginning, program counter and accumulator are set to 0. After fetching an instruction but before its execution, the program counter is incremented. You can assume that programs will terminate.

            Input Specification

            The input file contains several test cases. Each test case specifies the contents of the memory prior to execution of the program. Byte 0 through 31 are given on separate lines in binary representation. A byte is denoted by its highest-to-lowest bits. Input is terminated by EOF.

            Output Specification

            For each test case, output on a line the value of the accumulator on termination in binary representation, again highest bits first.

            Sample Input

            00111110
                        10100000
                        01010000
                        11100000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00111111
                        10000000
                        00000010
                        11000010
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        00000000
                        11111111
                        10001001
                        

            Sample Output

            10000111
            很好的題,很容易錯(cuò)。
            需要計(jì)算機(jī)組成原理的一點(diǎn)知識(shí),沒學(xué)過也能做。
            指令譯碼,(將二進(jìn)制轉(zhuǎn)化為十進(jìn)制并從中獲得操作類型和立即數(shù)x)可以用位運(yùn)算,
            指令執(zhí)行 pc,accu,立即數(shù)x都可以用int表示且是全局變量,memory用數(shù)組表示。
            有很多注意的地方,
            pc不能超過32;不能小于0.
            accu不能超過256.不能小于0.
            自己都沒有注意到。
            pc,accu,
            posted on 2009-07-24 10:59 luis 閱讀(305) 評(píng)論(0)  編輯 收藏 引用 所屬分類: 粗心題
            <2009年7月>
            2829301234
            567891011
            12131415161718
            19202122232425
            2627282930311
            2345678

            常用鏈接

            留言簿(3)

            隨筆分類

            隨筆檔案

            文章分類

            文章檔案

            友情鏈接

            搜索

            •  

            最新評(píng)論

            閱讀排行榜

            評(píng)論排行榜

            久久精品亚洲男人的天堂| 中文字幕无码久久人妻| 久久精品99久久香蕉国产色戒 | 久久棈精品久久久久久噜噜| 亚洲色婷婷综合久久| 国产亚洲婷婷香蕉久久精品| 国内精品欧美久久精品| 久久亚洲AV成人无码软件| 久久影院综合精品| 国产免费久久久久久无码| 亚洲综合伊人久久综合| 成人国内精品久久久久影院VR | 亚洲AV成人无码久久精品老人| 久久国产亚洲精品无码| 性高朝久久久久久久久久| 久久99精品久久只有精品| 欧洲国产伦久久久久久久| 国产精品禁18久久久夂久| 亚洲欧美久久久久9999| 亚洲国产精品久久久久婷婷软件| 亚洲伊人久久综合影院| 亚洲国产精品久久| 久久久久99精品成人片欧美| 亚洲国产一成久久精品国产成人综合 | 久久这里只有精品首页| 久久国产香蕉一区精品| 国产高清美女一级a毛片久久w| 久久超乳爆乳中文字幕| 久久久亚洲欧洲日产国码是AV| 激情综合色综合久久综合| 国产欧美久久一区二区| 久久精品水蜜桃av综合天堂| 伊人久久大香线蕉无码麻豆| 久久精品国产亚洲一区二区三区 | 久久久久久夜精品精品免费啦| 久久综合九色综合网站| 久久人人爽人人爽人人av东京热 | 亚洲国产日韩综合久久精品| 久久久久久曰本AV免费免费| 色婷婷噜噜久久国产精品12p | 久久人人爽人人爽人人片av高请|