{"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":172,"pdf_page":188,"physical_index":188,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"6e23d1e7c3cccda26b0d33827bcd1ad51087416b789ab0d5d1def75b3f6d426e"},"chapter":"编码隐匿在计算机软硬件背后的语言","content":"这时，电路会“记得”当保持位最后一次置1时数据端输入的值，数据端的变化对此没有影响。例如，数据端再置回0对输出将不会产生影响。\n\n这个电路称为电平触发的D型触发器，D（Data）表示数据端输入。所谓电平触发是指当保持位输入为某一特定电平（本例中为“1”）时，触发器才保存数据端的输入值（很快，我们将看到另一种形式的触发器)。\n\n通常情况下，当这种电路出现在书中的时候，输入端是不会被标记为保持位的，而是被标记为时钟（clock）。当然，这种信号并不是真正的时钟，但是在某些情况下它却具有类似时钟的属性，即它可以在0和1之间有规律地来回变化。但是现在时钟仅仅用来指示什么时候保存数据。\n\n通常把数据端简写为D，时钟端简写为Clk，其功能表如下所示。\n\n这个电路也就是所谓的电平触发的D型锁存器，它表示电路锁存住一位数据并保持它，以便将来使用。这个电路也可以被称为1位存储器。在本书的第16章将会介绍如何将多个1位存储器连接起来构成多位存储器。\n\n编码隐匿在计算机软硬件背后的语言\n\n172","previous_page":171,"next_page":173}