{"resolved":true,"match_type":"uuid","source_type":"original_book","book_id":"38270854-596f-4a26-8183-db8c968c6020","title":"编码 隐匿在计算机软硬件背后的语言","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787121181184","requested_by":"printed_page","book":{"source_type":"original_book","book_id":"38270854-596f-4a26-8183-db8c968c6020","id":"38270854-596f-4a26-8183-db8c968c6020","uuid":"38270854-596f-4a26-8183-db8c968c6020","title":"编码 隐匿在计算机软硬件背后的语言","normalized_title":"编码隐匿在计算机软硬件背后的语言","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787121181184","isbns":["9787121181184","0123456789","6044921875","3039331000","0000000000","0000000000000"],"parsed":true,"ai_readable":true,"document_type":"book","page_count":438,"navigation_url":"https://workshop.closeclaw.top/ai/book/38270854-596f-4a26-8183-db8c968c6020","title_url":"https://workshop.closeclaw.top/ai/title/%E7%BC%96%E7%A0%81%20%E9%9A%90%E5%8C%BF%E5%9C%A8%E8%AE%A1%E7%AE%97%E6%9C%BA%E8%BD%AF%E7%A1%AC%E4%BB%B6%E8%83%8C%E5%90%8E%E7%9A%84%E8%AF%AD%E8%A8%80","fixed_page_url_template":"https://workshop.closeclaw.top/ai/book/38270854-596f-4a26-8183-db8c968c6020/page/{printed_page}","path_api_url_template":"https://workshop.closeclaw.top/api/ai/book/38270854-596f-4a26-8183-db8c968c6020/page/{printed_page}","read_url":"https://workshop.closeclaw.top/api/ai/read/38270854-596f-4a26-8183-db8c968c6020","page_url":"https://workshop.closeclaw.top/api/ai/books/38270854-596f-4a26-8183-db8c968c6020/page","search_url":"https://workshop.closeclaw.top/api/ai/books/38270854-596f-4a26-8183-db8c968c6020/search"},"page":{"printed_page":175,"pdf_page":191,"physical_index":191,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"265a91c86e274c536837daef8134c7944ec9c81a3e9e60edaeedea2533c40ea1"},"chapter":"编码隐匿在计算机软硬件背后的语言","content":"如果选择端（Select）输入是1，那么或门的输出和B端的输入就是一致的。这是因为上面与门的输出和B端输入是一样的，而下面与门的输出是 $\\scriptstyle \\mathbf { 0 } _ { \\circ }$ 类似的，如果选择端的输入是0，那么或门的输出则和A端输入一致。总结起来如下表所示。\n\n改进后的加法器中包含了8个这样的1位选择器。所有的选择端输入信号都是连在一起的。\n\n改进后的加法器不能很好地处理进位输出（CO）信号。如果两个数的相加使得进位输出信号为1，那么当下个数被加进来的时候，这个信号将被忽略掉。一个可能的解决方案是将加法器、锁存器、选择器均设置为16位宽，或者至少应该比你可能遇到的最大的和的位数多一位。这个问题留到第17章具体讲述。\n\n对于加法器来说，一个更好的改进方法是去掉一整排8个开关。但是首先要对D触发器做一些修改，为它加一个或门和一个称为清零（Clear）的输入信号。清零信号通常为0，但当它为1时，Q输出为0，如下图所示。\n\n无论其他信号是什么，清零信号总是强制使Q输出为0，以达到使触发器清零的目的。\n\n14 反馈与触发器\n\n175","previous_page":174,"next_page":176}