UAA326A04 HIEE300024R4 ABB? UAA326A041、指令寄存器用來(lái)存放正在執(zhí)行的指令。指令分成兩部分：操作碼和地址碼。操作碼用來(lái)指示指令的操作性質(zhì)，如加法、減法等；地址碼給出本條指令的操作數(shù)地址或形成操作數(shù)地址的有關(guān)信息（這時(shí)通過(guò)地址形成電路來(lái)形成操作數(shù)地址）。

有一種指令稱為轉(zhuǎn)移指令，它用來(lái)改變指令的正常執(zhí)行順序，這種指令的地址碼部分給出的是要轉(zhuǎn)去執(zhí)行的指令的地址。 2、操作碼譯碼器：用來(lái)對(duì)指令的操作碼進(jìn)行譯碼，產(chǎn)生相應(yīng)的控制電平，完成分析指令的功能。 3、時(shí)序電路：用來(lái)產(chǎn)生時(shí)間標(biāo)志信號(hào)。在微型計(jì)算機(jī)中，時(shí)間標(biāo)志信號(hào)一般為三級(jí)：指令周期、總線周期和時(shí)鐘周期。微操作命令產(chǎn)生電路產(chǎn)生完成指令規(guī)定操作的各種微操作命令。這些命令產(chǎn)生的主要依據(jù)是時(shí)間標(biāo)志和指令的操作性質(zhì)。該電路實(shí)際是各微操作控制信號(hào)表達(dá)式（如上面的A→L表達(dá)式）的電路實(shí)現(xiàn)，它是組合邏輯控制器中最為復(fù)雜的部分。 4、指令計(jì)數(shù)器：用來(lái)形成下一條要執(zhí)行的指令的地址。通常，指令是順序執(zhí)行的，而指令在存儲(chǔ)器中是順序存放的。所以，一般情況下下一條要執(zhí)行的指令的地址可通過(guò)將現(xiàn)行地址加1形成，微操作命令“1”就用于這個(gè)目的。如果執(zhí)行的是轉(zhuǎn)移指令，則下一條要執(zhí)行的指令的地址是要轉(zhuǎn)移到的地址。該地址就在本轉(zhuǎn)移指令的地址碼字段，將其直接送往指令計(jì)數(shù)器。 微程序控制器的提出是因?yàn)榻M合邏輯設(shè)計(jì)存在不便于設(shè)計(jì)、不靈活、不易修改和擴(kuò)充等缺點(diǎn)。UAA326A04 HIEE300024R4,UFC718AE101 HIEE300936R0101，UFC718AE01 HIEE300936R0001??Product introduction:

There are instructions called transfer instructions, which are used to change the normal order of execution of instructions. The address section of such instructions gives the address of the instruction to be transferred to execution. 2. Opcode decoder: used to decode the opcode of the instruction, generate the corresponding control level, and complete the function of analyzing the instruction. 3, timing circuit: used to generate time marker signal. In a microcomputer, the time flag signal usually has three levels: instruction cycle, bus cycle and clock cycle. Microoperation command generation The circuit generates various microoperation commands that complete the operation specified by the instruction. These commands are generated primarily based on the time flag and the operational nature of the instruction. The circuit is actually the circuit realization of the expression of each microoperation control signal (as above A→L expression), which is the most complex part of the combinatorial logic controller. 4, Instruction counter: used to form the address of the next instruction to be executed. Normally, instructions are executed sequentially, and instructions are stored sequentially in memory. So, in general, the address of the next instruction to execute can be formed by adding 1 to the current address, and the microoperation command "1" is used for this purpose. If a transfer instruction is executed, the address of the next instruction to be executed is the address to be transferred to. This address is in the address field of this transfer instruction, sending it directly to the instruction counter. Microprogram controller is proposed because combinatorial logic design is not easy to design, not flexible, not easy to modify and expand and other shortcomings.