6809: Difference between revisions
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=Frequency= | =Frequency= | ||
Set reader to FREQ, put black probe to GND, red probe to 38 / 39 to measure CPU clock | Set reader to FREQ, put black probe to GND, red probe to 38 / 39 to measure CPU clock.<br> | ||
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= | =External links= | ||
Revision as of 08:35, 6 September 2010
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
-
MC6809 Datasheet
