CC430 MCU digital IO port learning

   When I first came into contact with CC430 microcontroller, I felt a little confused, but it was a good thing . However, when you read the program carefully, some code styles are refreshing to me, a newborn calf. I have never seen them before. It's no wonder, after all, I still have a lot to learn . CC430 is a microcontroller with wireless transceiver function based on MSP430 as the core. It is designed for sensor networks, making it involved in the vast space of the Internet of Things. With in-depth learning, I found that if you have learned MSP430 programming before, then using CC430 is also a piece of cake. The programming style is completely similar (if you have not used MSP430, you can't say it is similar ).

   People always like to pick the softest persimmons. For personal style, learning this microcontroller starts from the digital IO port . Some people may think that we should first analyze it from the CPU architecture. This aspect is indeed very important, but for a pragmatist , the chip is analyzed from the perspective of application. Of course, this analysis is not comprehensive enough, but after reading it, there is absolutely no problem in using it. Otherwise, I'd better publish a book. Based on the importance of CPU architecture, you should be familiar with this chip and then come back to analyze it. At that time, you will have more experience . Wow, why did I say so much nonsense? I'm almost a chatterbox .

The prologue slowly opens...

The main functions of the IO port: 1. Ordinary IO port and special function IO port (AD conversion port)            PxSEL

               2. IO port direction (input or output)                      PxDIR

               3. Input and output status (high or low)                    PxIN   or   PxOUT

                4. Use of pull-up resistor during input (pull-up or pull-down or disable)   PxREN

               5. IO port interrupt function (only P1 and P2 ports)                PxIFG, PxIE, PxIES, PxIV

PxSEL = 0 Normal IO port function

     = 1 Peripheral module function----IO port interrupt function is disabled at this time

PxIN   = 0 Normal IO port input is low level

     = 1 Normal IO port input is high level

PxOUT  = 0 The output of the common IO port is low level

     = 1 The output of the common IO port is high level

PxDIR, PxREN, PxOUT follow me

PxDIR          PxREN          PxOUT          IO Configuration

 0              0              X              Input

 0               1               0              Input and pull down

 0               1               1              Input and pull-up

  1               X              X              Output

Description: When IO is set to input state, PxOUT is assigned a new task to set the pull-up and pull-down process

Interrupt description: PxIFG and PxIE meet each other often, they are old friends, so I won’t introduce them.

         P1IV register, when reading the interrupt, it is up to this brother to select which interrupt vector.

         PxIES register, interrupt mode (rising edge or falling edge)

                      Bit is 0: When the rising edge occurs, the PxIFGx interrupt flag is set.

                      Bit is 1: When the falling edge occurs, the PxIFGx interrupt flag is set.

That’s all I have to say about IO . If you have any questions or errors, please leave your comments and we can discuss together.