M68HC05E24/D2
3-3
MOTOROLA
3.1.3 Clock Source Select Headers (J3, J4)
Jumper headers J3 and J4 determines the source of the clock signal. The diagram below
shows the factory configuration of these jumpers: the fabricated jumper between pins 2 and 3
of J4 selects the E24EM canned oscillator clock source.
1
2
3
FABRICATED
JUMPER
FABRICATED
JUMPER
J3
FABRICATED
JUMPER
(J4)
Target
1
2
3
FABRICATED
JUMPER
J4
EM
MMDS
Alternatively, you may use a clock source originating from the MMDS05 control board. To do
so, reposition the J4 jumper between pins 1 and 2. The MMDS OSC command can then be
used to select clock frequency.
Jumper J3 can be used to select between an internal generated clock or a external clock
generated by the target system. If the target clock is selected by placing the jumper on J3
between pins 1 and 2, the position of J4 is not important.
NOTE: The only valid position of the J1 fabricated jumper is between pins 2 and 3 when using
the E24EM as part of an EVS system.
Freescale Semiconductor, I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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