AT89C4051

8-bit Microcontroller

Pinout

DIP20
            +---\/---+
    RST/Vpp | 1    20| Vcc
  (RXD)P3.0 | 2    19| P1.7
  (TXD)P3.1 | 3    18| P1.6
      XTAL2 | 4    17| P1.5
      XTAL1 | 5    16| P1.4
(*INT0)P3.2 | 6    15| P1.3
(*INT1)P3.3 | 7    14| P1.2
   (TO)P3.4 | 8    13| P1.1(AIN0)
   (T1)P3.5 | 9    12| P1.0(AIN0)
        GND |10    11| P3.7
            +--------+

Frequency

DIP20
Set reader to FREQ, put black probe to GND, red probe to 4,5 to measure CPU clock

Files

• 
  At89C4051 Datasheet