"Big Talk Storage 2" Reading notes-2nd Chapter IO Dafa into the world of computer IO

IO Path--Bus

• Pre-knowledge

The brain uses neural networks to transfer calculated information to these "devices", such as arms, legs, and muscles, to drive these "device" movements. The computer uses the bus to transfer the calculated data to external devices, such as monitors, printers, etc.

1. simplex
Simplex means a can only signal, and B can only receive signals, communication is one-way, like the lighthouse in the ship-beacon light signal and the ship can only receive signals to ensure that they are driving on the correct route.

　　2, half Duplex
Half-duplex means a can signal to the b,b can also send a signal to a, but these two processes can not be carried out simultaneously.

The most typical example is the same walkie-talkie we see in the film and television works:

007: Call the HQ, request support, over
HQ: Roger, reinforcements will arrive in 5 minutes, over.

007:5 minutes so long?! Be quick! Over

Headquarters:.....
GAME over
Here, each party after saying a sentence to say a over, and then switch to the receiving State, but also tell the other side-you can speak. If both sides are at the same time, or at the same time in the state, it will not communicate properly.

　　3, Full Duplex
Full duplex is a step further than half-duplex. B can also signal A to B when a signal is given.

A typical example is making a phone call.

• Computer Bus structure

Computer bus operating mode: half Duplex

bit width of bus or device: number of bars per data bus

Number of CPU bits: The total number of lines before the internal register to the calculated unit

PCI bus: A bus technology that is commonly used by desktops and servers to connect a South bridge to a peripheral. PCI address bus, data bus time-sharing multiplexing.

system bus (front-end bus): The bus that the CPU connects to the North Bridge

Memory bus: The bus that the memory connects to the North Bridge

Bus Frequency: The data transfer rate when the CPU accesses data externally

CPU Self Frequency: Frequency of the circuit generated by the CPU operation

Big Talk Storage 2 reading notes-2nd Chapter IO Dafa into the world of computer IO