8051 P Registers

Port Registers

• Address: P0 – 0x80, P1 – 0x90, P2 – 0xA0, P3 – 0xB0
• Size: 8-bit
• Bit and Byte addressable.
• There are 4 port registers: P0, P1, P2, and P3.
• Each register is mapped to corresponding IO port.
• IO pins can be accessed using these registers.

AD0 – AD7	Data bus and lower order address bus for external memory interfacing.
A8 – A15	Address bus for external memory interfacing.
RD	Active Low Output. External memory Read control signal.
WR	Active Low Output. External memory Write control signal.
T1	External input to Timer 1.
T0	External input to Timer 0.
INT1	Input. External interrupt source.
INT0	Input. External interrupt source.
TxD	Output. Transmits serial data.
RxD	Input. Received serial data.

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Related topics:
8051 Registers   |   8051 Program Counter   |   8051 R Registers   |   8051 SFR   |   8051 Stack   |   8051 Stack Pointer   |   8051 Data Pointer   |   8051 PCON Register   |   8051 TCON Register   |   8051 TMOD Register   |   8051 Timer Registers   |   8051 SCON Register   |   8051 SBUF Register   |   8051 IE Register   |   8051 IP Register   |   8051 PSW Register   |   8051 A Register   |   8051 B Register

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