What Is a Control Bus?

Control Bus (ControlBus) is referred to as CB. The control bus is mainly used to transmit control signals and timing signals. Among the control signals, some are sent from the microprocessor to the memory and input / output device interface circuits, such as: read / write signals, chip select signals, interrupt response signals, etc .; others are also fed back to the CPU, such as interrupt request signals, Reset signal, bus request signal, device ready signal, etc. Therefore, the transmission direction of the control bus is determined by specific control signals, which are generally bidirectional. The number of bits of the control bus depends on the actual control needs of the system. The actual situation of controlling the bus depends on the CPU. ^[1]

The characteristics of the control bus CB (ControlBus) are: in the form of unidirectional, bidirectional, bi-state, etc., it is the most complex, flexible and powerful function in the bus, and its number, type and definition are different.

The control bus is a collection of various signal lines, and is a common channel for transmitting data, addresses, and control information between various computer components.

According to the position relative to the CPU and its chip:

On-chip bus: refers to the internal

1,

1. of the bus

One operation process of the bus is to complete the transmission of information between the two modules. The master module and the slave module start the operation process. Only one master module can occupy the bus at any one time. ^[2]

A bus is a collection of signal lines that is a common channel for transmitting information between modules. Through it, various data and commands can be transferred between computer components. In order to enable products from different vendors to be interchanged and give users more choices, the technical specifications of the bus must be standardized.

The standard formulation of the bus must be carefully considered and strictly regulated. The bus standards (technical specifications) include the following sections:

Mechanical structure specifications: The module size, bus plug, bus connector, and installation size are all uniformly specified.

Functional specifications: Each signal line (name of the pin), function, and working process of the bus must have uniform regulations.

Electrical specifications: effective level of each signal line of the bus, dynamic conversion time, load capacity, etc.