8051 port configuration
- 1. INTEL 8051-PORT 1 PREPARED BY B.SARAVANAMANIKANDAN ASSISTANTPROFESSOR Kongunadu college of engineering and technology
- 2. Port-1 Configuration KNCET EEE Department
- 3. • Port 0 and 2 together can be used to address the external memory. Port 0 can also be used to exchange data from the external port. accessing 64K bytes of external memory, it needs a path for the 16 bits of the address. P0 gives lower Byte of Address. KNCET EEE Department
- 4. PORT 1 • Port 1 is a bidirectional I/O port with internal pull ups • The circuit has 3 FET. • When port 1 as input port logic level is loaded to the latch .This is will turn off the FET 1. • This will effectively float the port pin to high impedance state and will be connected the pin read buffer. • The pin is at logic level 1 is at instant. • An external device may place a 0 by driving the pin ground or it may place a 1 on pin by leaving it at logic state. KNCET EEE Department
- 5. • When used as output port the value will be loaded to the latch. • The latches which contain level 1 will turn off FET T1 and will drive the pin high through pull register formed by T2 and T3. • This will ground the pin and it will show logic level 0. • The latches containing level 0 will turn on FET 1 KNCET EEE Department
- 7. PORT 2 • Port 2 can be used as a bidirectional I/O port • It can used as a higher order internal bus for external memory interface • When used as a input port logic level is stored in latch • T1 is turned of and floats in high impedance state. The pin is directly connected pin read buffer. • The external device can place 0 or 1. • When used as output port the working of port is similar to port 1 that means the latch o will turn on FET T1. • Thus ground the pin • The latch containing 1 will turn off T1 and pin will be driven to logic level 1. • When port is used to higher order address bit for external memory access the control . They are directly connected pin trough FET KNCET EEE Department
- 8. PORT 3 KNCET EEE Department
- 9. PORT 3 • Port 3 can be used as a bidirectional I/O. • Different pins of port3 also facilitate alternate functions. • The functions port3 pins is either under the control of port latches under the control of SFR. • These pins are individually programmable unlike other ports where alternate functions of all port pins are programmed together. • It read by two ways read latch signal read pin signal KNCET EEE Department
- 10. Conclusion: • The port configuration of 8051 microcontroller are explained in detail manner. KNCET EEE Department