of the MCS-51 Family, as listed below: Pin P3.0 P3.1 P3.2 P3.3 P3.4 P3.5 P3.6 P3.7 Name RXD TXD INT0 INT1 T0 T1 WR RD Alternate Function Serial input line Serial output l.

The Idle mode freezes the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue func.

VCC: Supply voltage during normal, Idle and Power Down operations. VSS: Circuit ground. Port 0: Port 0 is an 8-bit open drain bidirectional I/O port. As an output port each pin can sink several LS TTL inputs. Port 0 pins that have 1's written to them.

P80C51

P80C51X2

P80C521

P80C528

P80C52X2

P80C541

P80C54X2

P80C552

P80C557E4

P80C557E6

P80C557E8

P80C562

P80C58X2