What are the uses of port 0 and port 1 of 8051?

When connecting an 8051/31 to an external memory, port 0 provides both address and data. Port 1 is used as input and output. Upon reset, port 1 is configured as an input port. Port 2 is also used as input or output.

What is the function of port 1?

The function of Port 1 – I/O port: Consequently, it connects to the input buffer. When Port 1 is functioning in the capacity of an output port, the latch is given a ‘LOW’ signal (00H). This turns the FER (Field Effect Transistor) o. The pull-up resistor is OFF, and the port is used as an output port.

What is the function of I O Ports in 8051 microcontroller?

8051 microcontrollers have 4 I/O ports each of 8-bit, which can be configured as input or output. Hence, total 32 input/output pins allow the microcontroller to be connected with the peripheral devices. Pin configuration, i.e. the pin can be configured as 1 for input and 0 for output as per the logic state.

What is the dual role of port 0 in 8051?

Dual Role of Port 0 and Port 2 While connecting an 8051 to external memory, Port 0 can provide both address and data. The 8051 microcontroller then multiplexes the input as address or data in order to save pins. Port P2 is also designated as (A8– A15), while Port 0 provides the lower 8-bits via A0–A7.

Why do you need port 0 for pull up register?

When we use external pull-ups it becomes general purpose port. Again, port 0 is open drain hence it requires pull-ups and all other ports are not having open drain its not left to user. If port 0 has to be used as i/o port its must to connect pull up resistor.

Which of the following is an alternate function of P3 0 Pin in 8051 microcontroller?

–> An alternate function of port pin P3. 0 (RXD) in the 8051 is serial port input. Hope this helps you!

Which port is a simple port in 8051 microcontroller?

Port 3 as simple output port • When port 3 is used as output port, the latched pins that are programmed to 0, will cause the lower FET to turn on, the internal pull up to turn off and input to the circuit is logic 0.

What is the address range of port 0 in 8051?

It is 16 bit register means the 8051 can access program address from 0000H to FFFFH.

Why Port 0 must be connected with pull up registers before using them for input output?

To use the pins of port 0 as both input and output ports, each pin must be connected externally to a lOK-ohm pull-up resistor. This is due to the fact that PO is an open drain, unlike PI, P2, and P3, as Figure 4-2. Port 0 with Pull-Up Resistors we will soon see.

Why port 0 of 8051 microcontroller is known as true bidirectional What is the difference between read latch and read pin operation for port line?

Each port of 8051 has bidirectional capability. Port 0 is called ‘true bidirectional port’ as it floats (tristated) when configured as input. When control is ‘1’, the port is used for address/data interfacing. When the control is ‘0’, the port can be used as a normal bidirectional I/O port.

How many input and output ports are there in 8051 microcontroller?

Microcontrollers 8051 Input Output Ports. 8051 microcontrollers have 4 I/O ports each of 8-bit, which can be configured as input or output. Hence, total 32 input/output pins allow the microcontroller to be connected with the peripheral devices. Pin configuration, i.e. the pin can be configured as 1 for input and 0 for output as per the logic state.

What is the use of port-0?

Port-0 can be used as a normal bidirectional I/O port or it can be used for address/data interfacing for accessing external memory. When control is ‘1’, the port is used for address/data interfacing. When the control is ‘0’, the port can be used as a bidirectional I/O port. Let us assume that control is ‘0’.

What is the I/O pin configuration in microcontroller?

Pin configuration, i.e. the pin can be configured as 1 for input and 0 for output as per the logic state. Input/Output (I/O) pin − All the circuits within the microcontroller must be connected to one of its pins except P0 port because it does not have pull-up resistors built-in.

What is the function of port-1?

Port-1 does not have any alternate function i.e. it is dedicated solely for I/O interfacing. When used as output port, the pin is pulled up or down through internal pull-up. To use port-1 as input port, ‘1’ has to be written to the latch.