1: What is a full-duplex serial port? 2: What is a mask ROM? 3: What is "interrupt" and "live protection"? -------------------------------------------------- ------------- 1: What is a full-duplex serial port? == In the data, it can also receive data, and there is no effect on serial port 2: What is mask ROM? == Before leaving the factory to write the program to the ROM, it is called mask ROM, it is A ROM that can only be written once. 3: What is "Interrupt" and "On-site Protection"? == Interrupt is a hardware event generation, causing the CPU to interrupt from the original program, execute another program, and then return. When running in another program, you need to protect the field protection, so as not to affect the original procedure ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------- 1, the full duplex finger at the same time, the data can send or receive, half The duplex can not be received while receiving. It can not send full duplex at the same time. It is relatively two, ......... 3, I will give you an example: Interrupt: It is equivalent to you are reading, Suddenly someone called, you should pick up the phone and answer the phone response to the interrupt to take the phone and others. It is equivalent to the interrupt service. The phone is equivalent to the interruption return and on-site protection is equivalent to you to pick up the phone. Seeing a bookmark in the current page, then wait for the phone to turn back to continue, and in the program, when the program is to execute the interrupt program, some data is protected, and the interrupt service is executed. Retrieve the protection data and then talk about the priority of the interruption: Suppose you just call you is your friend, you talk about it, suddenly your phone rang, you take out, ... · # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ # ¥ % ¥%, actually the head boss, no way, you have to say to a friend, you first wait, I will pick up the phone, then you will take the mobile phone and the boss, wait until the time is finished, continue to talk to your friends. . So during this process, the call to the boss is also responsive, and you are now interrupting the service program (picking friends), no way, the boss's "interruption" priority is higher, so I have to take friends. The content of the chat first, talk to the boss, wait until the end of the card (this interrupt service program is executed), return to the previous interrupt service program (that is, continue to talk to friends) but if you are in contrast, for example, if you are Telephone, you are tight, when your friend calls, there is no way, you can't call the boss for a while, don't answer the phone, that is, the high-level interrupt service program is low in the service program. Interrupt. (I just give an example, not to say that friends have not ordered it, I hope everyone should not misunderstand)
