1, HC5The 95 is featured with 8-bit shift registers and a memory, tri-state output function. Shift registers and memory are separate clocks. Data is entered at the rising edge of the SHcp and entered into the memory register at the rising edge of the STcp. If two clocks are connected, the shift register is always one pulse ahead of the storage register.
2, register: register is a storage device, can temporarily store data or instructions. Registers are usually used to store temporary variables, addresses, flags and other information that the CPU needs to use when processing data. It works by an electronic trigger,When data is entered, the register stores the data internally and can read the stored data when needed. In a computer system, the number and bit width of registers often affect the running speed of the system.
3, we know that 74HC595 is the data string conversion, that is, the data (8bit) serial input, parallel output. Serial parallel these concepts are not much to say, not clear self-check data.
4, there are many ways to drive the digital tube, but the 74HC595 shift register stands out because of its unique advantages. It uses 3-pin control and can drive any numberCode tube, significantly saving I/O resources. The core of this chip is the serial input of DS and the parallel output of Q0~Q7, which realizes the conversion of serial data to parallel display.
5, HC595 is a drain open output CMOS shift register. If you do not send a clear or new command after the power failure, the previous data will be maintained.
6. HC595 is an 8-bit SIPO (Serial-In-Parallel-Out) shift register. It has 8 output pins, while only 3 are requiredThe data is stored to an 8-bit parallel output register.
These chips can be extended to the P0 port to provide more I/O ports. The parallel expansion method adopts 74HC244 chip with three-state buffer and 74HC377 chip with output latch for parallel expansion of P0 port, which can realize more I/O ports. Among them, 74HC244 chip can realize the input and output control of P0 port, and 74HC377 chip can realize the output control and latch control of P0 port.
HC240 circuit 1Y2 output high level, relay release, contact breakOpen, no signal output; When S1 is released, the 1Y2 output low level, the relay draws, the contact closes, and the timing square wave signal generated by CD4060 can be output.
mm74hc is a Schmidt flip-flop logic chip. mm74hc is a Schmidt flip-flop logic chip, which uses binary as the principle to realize the integrated single path of logic judgment function. Logic chips also have another name "programmable logic devices" (English: Programmable&Logic&Device, abbreviated to PLD) is an electronic part, electronic components, in shortIt is also a kind of integrated circuit, chip.
hc4040 is a 12-level binary counter. The working voltage of the power supply is 2V ~ 6V. Connect pin 8 to the power supply ground and pin 16 to the positive power supply VDD. Pin 11 is the clear end, the high level is effective, you will connect pin 11 to the power source when used. You are going to divide the square wave to pin 10 of the clock. Q2=7 pin, 7 pin output is 4 frequency division.
HC74 is a double-D flip-flop with a single input. A chip encapsulates two identical D triggers, each of which has only one D terminal, both of which have a direct 0 terminal RDAnd directly set one SD to a low level. CP rising edge triggered.
2, HC595 is a serial shift register, two chips cascaded, the serial output pin of the chip U1 connected to the serial input pin of the chip U2. When the serial port inputs 8 bits of data data1, the data data1 is in the U1 chip. When the serial port inputs 8 bits of data data2 again, data1 enters the chip U2, and data2 remains in the chip U1.
3, RCK = 1; // Reset to high, resulting in shift on the clockAscending edge, ascending edge when the shift register data into the data storage register, update the display data.
4, since we want to use 74hc595, then we must write a 595 driver, in order to simplify the following operation.