What is the difference between registers and latches, and what is the difference between memory and

latch. Difference from registers:

1.The registers are synchronous clock control, while the latches are potentiometric signal control. The latch is generally determined by level.

Signal control, which is level-sensitive. Registers are generally signaled by clocks.

Signal control, edge-sensitive.

2.The output of the register usually does not change with the change of the input terminal, and only when the clock is active, the data of the input end is sent to the output terminal (into the register), and the output terminal of the latch usually changes with the change of the input terminal, and only when the latch signal arrives, the state of the output terminal is latched, so that it no longer changes with the change of the input terminal.

Register. in the actual number system.

, it is common to put synchronous timing logic circuits that can be used to store a set of binary **.

Called a register Since there is a memory function in the flip-flop, the flip-flop can be used to conveniently form registers. Since a flip-flop can store one bit of binary code, connecting the clock ports of n flip-flops can form a register that stores n-bit binary code.

latch. D-flip-flop is controlled by several bells.

It is a sequential logic circuit that can store multiple binary ** at a time. The data is valid later than the clock signal. This means that the clock signal comes first, and the data signal comes later. In some combinator circuits, latches are sometimes used as data registers.

<> take a look at the chapters on flip-flops, registers, and latches in this book, and you might find something to gain. I was going to continue with you yesterday, but you're all mine.

Registers, as the name suggests, are where data is kept. There are different explanations in different environments.,I won't introduce this.,Typing is tired.。

Latches are used to store data for exchange, so that the data is stable and remains unchanged for a period of time until new data replaces it.

Registers and latches are both used to temporarily store data devices, there is no difference in nature, but the output of the register usually does not change with the change of the input end, only when the clock is valid will the input data be sent to the output end (into the register), and the output of the latch usually always changes with the change of the input end, only when the latch signal arrives, the state of the output end is latched, so that it no longer changes with the change of the input end. Got it

Isn't your understanding quite in line with what you found?

The differences between registers and memory are as follows:

1. Memory function: store instructions and data, and can be directly accessed by the ** processor (CPU).

2. Register function: the data in the register can be used to perform arithmetic and logical operations; An address stored in a register can be used to point to a certain location in memory, i.e., addressing; It can be used to read and write data to the peripherals of the computer.

3. The speed of the register is much faster than the speed of the main memory, because the capacity of the register is limited, so the data that does not need to be operated is stored in the main memory, and the data in the main memory must be put into the register device to be able to operate.

4. To put it simply: the register is the place where the data is manipulated, and the memory is the place where the data is stored.

5. The register structure usually refers to the basic RS flip-flop derived from the D flip-flop, which is composed of some NAND gate structure, the overall integration in the CPU, and the read/write speed is basically matched with the speed of the CPU, but because of the superior performance, it is expensive, and the general good CPU only has a few MB of second-level cache and first-level cache.

6. CPU memory, usually refers to the hard disk, U disk and other devices can save the power after the power is cut off, the data capacity is generally relatively large, the disadvantage is that the read and write speed is very slow, the read and write speed of ordinary mechanical hard disk is usually about 50MB s. Memory and registers are multi-layered storage mechanisms for slow memory reads and writes.

The latch can change state at the level of a specific input pulse.

Latching is the temporary storage of a signal to maintain a certain level of state. The main function of the latch is to cache, then to complete the problem of asynchronous between the high-speed controller and the slow peripherals, then to solve the problem of driving, and finally to solve the problem that an I-o port can both output and input. A latch is an input that uses level control data, and it includes a latch without enable control and a latch with enable control.

Latch application scenarios:

1. The latch is mostly used in integrated circuits, as a storage element of timing circuits in digital circuits, and sometimes uses latches as data scratchpads in some combinator circuits.

2. It can also be applied separately after being packaged as an independent product, and the data is effectively delayed by the clock signal. This means that the clock signal comes first, and the data signal comes later.

3. In some applications, an external latch is required on the IO port of the MCU. For example, when a microcontroller is connected to an off-chip memory, a latch is connected to realize the multiplexing of addresses. Suppose that the 8 I O pins of the MCU port are used for both address signals and data signals, then the address can be latched first.

The above content reference:

The latch is to latch the current state, so that the data sent by the CPU is latched at the output of the interface circuit for a period of time, and the state does not change until it is unlocked. There are also chips that have latches, such as chip 74LS244, which can be latched by setting a pin high, and the output will remain in its current state until the pin is cleared of 0.

In terms of LED and digital tube display, in order to maintain a data display, it is often necessary to continuously and quickly refresh. Especially on these display devices to be gated such as four-segment eight-bit digital tubes. Within the refresh rate that humans can accept, it needs to be refreshed about every 30 milliseconds.

This greatly consumes the processing time of the processor, consumes the processing power of the processor, and wastes the power consumption of the processor.

The use of latches can greatly relieve the pressure on the processor in this regard. When the processor transfers data to the latch and latches it, the output pin of the latch retains the data until the next time new data is latched. In this way, the processing time of the processor and the IO pin can be released until the display content of the digital tube remains unchanged.

As you can see, the processor processes time only when the display content changes, which is a very small part of the overall display time. The processor has more time to perform other tasks after processing. This is where latches come into play in LED and digital tube displays:

Saves valuable MCU time.

Register. The differences with the scratchpad are: different operations, different classifications, and different mode state families.

First, the operation is different.

1. Register: The register is used to temporarily store instructions, data and addresses, and is a high-speed storage component with limited storage capacity.

2. Scratchpad: The scratchpad is used to temporarily store the bus that is closed by the data.

or an operand from a generic register and treat it as another operand.

Second, the classification is different.

1. Registers: Registers are divided into general registers, special registers and control registers.

2. Register: Scratchpad is divided into instruction scratchpad (IR) and program counter.

PC) and an accumulator (ACC).

Third, the way is different.

1. Register: The register adopts serial mode, and several clock pulses are used to complete the input or output operation, and the working speed is slow, but only one input or output data line is needed, and the transmission line is few, which is suitable for long-distance transmission.

2. Register: The scratchpad adopts a parallel mode, and only one Shishan Clock pulse can complete the data operation, and the working speed is fast, but it requires N input and output data lines.