In the digital circuit, the microcontroller real-time as a part of the control system, and the microcontroller in the program is written for its circuit, can achieve these functions, there is no doubt that the microcontroller pin played a huge role. And single chip microcomputer pin according to the function can be divided into what several categories?

The pin of MCU can be roughly divided into four categories according to its function: power supply, clock, control and I/O pin.

Power supply:

1. VCC - chip power supply, connected to +5V;

2. VSS - grounding terminal;

clock :XTAL1, XTAL2 - crystal oscillation circuit inverting input and output end.

Control line: There are 4 control lines

(1)ALE/PROG: address latch allowed/on-chip EPROM programming pulse ① ALE function: used to latch the low 8-bit address sent from port P0 ② PROG function: chip of the EPROM inside the chip, during the EPROM programming, this pin input programming pulse.

(2)PSEN: external ROM read selection communication number.

(3)RST/VPD: reset/standby power supply.

Reset (RST) function: resets the signal input.

VPD function: Connects to the standby power supply in case of a Vcc power failure.

(4)EA/Vpp: internal and external ROM selection/on-chip EPROM programming power supply.

EA function: internal and external ROM selection terminal.

Vpp function: chip with EPROM, during EPROM programming, apply programming power Vpp.

the I/O lines

Taking the commonly used 80C51 microcontroller as an example, there are a total of four 8-bit parallel I/O ports: P0, P1, P2, P3, a total of 32 pins. P3 port also has a second function for special signal input and output and control signals (belong to    the control bus).

The above is about the single chip microcomputer pin according to the function is divided into several categories of all content to share, I believe that after reading can bring help to you. Yufan micro provides ic wafer production and packaging customization,    as a nine level agent, has more than 10 years of SCM chip application design experience, for the majority of electronic products manufacturers to provide MCU application function customization development services.