What does p2=0xFF, 0xFF mean in microcontroller C?
0x is the prefix of hexadecimal, hexadecimal is a representation of data in the computer;
hexadecimal 0xFF is binary 1111111111, converted to decimal is 255;
decimal representation is different, is every 16 into 1, it consists of 0-9, A-F, the letters are not case-sensitive, such as 10 With the hexadecimal representation is A;
P2=0xFF, that is, P2.0 ~ P2.7 all set to 1, that is, P2 = 1111111111, of course, it is not P2 = 0x01;
Microcontroller c language XBYTE use
The use of keil to develop microcontroller program, in the header file absacc.h, there is a macro like XBYTE. Its definition is #defineXBYTE((unsignedcharvolatilexdata*)0)You can use XBYTE to access external RAM, you can also use XBYTE to access the extended I/0 devices;
About the control of the I/O is as follows, the low byte indicates the P0 port, the high byte indicates the P2 port. The P2 port is usually used as a control port, while P0 is usually used as a data port; eg: XBYTE[0x8800]=buz_stu; where P2 is used for control, and the data from P0 is the state of buz_stu.
Note: Here the Intel bus is utilized for the access, then there are timing issues, in C, these are done for you, so no need to think about it
What does dig mean in microcontroller C?
In microcontroller C, dig is usually an abbreviation for DigitalInput. It is used to read the state of a digital input signal from an external source (e.g., a sensor input) and is typically used to detect, measure, and control the state of an external device.
In C, parameters such as port address and pin number can be used to control digital inputs and outputs. The C language is typically used to write control programs that include processing digital inputs, controlling digital outputs, and performing other tasks. In microcontroller applications, input and output functions such as dig are usually standard library functions provided by the chip manufacturer, and the programmer only needs to call these functions to realize specific input and output functions.