6809

8-bit Microprocessor

Pinout

DIP40
        +---\/---+
    GND |1     40| *HALT
   *NMI |2     39| EXTAL
   *IRQ |3     38| XTAL
  *FIRQ |4     37| *RST
     BS |5     36| MRDY
     BA |6     35| Q
    VCC |7     34| E
     A0 |8     33| *BREQ
     A1 |9     32| R/*W
     A2 |10    31| D0
     A3 |11    30| D1
     A4 |12    29| D2
     A5 |13    28| D3
     A6 |14    27| D4
     A7 |15    26| D5
     A8 |16    25| D6
     A9 |17    24| D7
    A10 |18    23| A15
    A11 |19    22| A14
    A12 |20    21| A13
        +--------+

Frequency

Set reader to FREQ, put black probe to GND, red probe to 38 / 39 to measure CPU clock.
20100906 Note from Jonathan Gevaryahu: check pin 39 (XTAL) of the 6809; if this pin is grounded, the clock comes in purely through pin 38 (EXTAL) and can be measured there. If the pin is NOT grounded, measure pin 34 (E) or pin 35 (Q) and multiply the resulting frequency by 4 to get the actual clock frequency the chip is being fed, since if XTAL is not grounded, measuring on EXTAL or XTAL may affect the clock to the chip and throw off your measurement.

External links

6809 page on Wikipedia
6809 page on CPU-World

Files

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  MC6809 Datasheet