Motorola MCU 68HC912D60 - Manual (Page 11)

11
JUMPERS
MON-SEL JUMPER
Selects which firmware monitor in External EPROM (U6/7) the board will execute upon reset
in expanded mode with monitor enabled by CONFIG SWITCH position 4.
ON Mon12 Debug Monitor
OFF Third party firmware support (NoICE, Metrowerks, etc.)
PG_PULL / PH_PULL JUMPERS
Pull up or Pull down I/O line bias resistor option jumpers. When port G or Port H are
configured as inputs these options select which way the internal pull resistor’s operate.
Port H should be in the pull down state if KEYPAD is used.
GND Pull Down active (default)
+5V Pull Up active
JP1 Oscillator Select JUMPER
Provides enabling and Disabling of the internal PLL and external clock oscillator X1.
Default configuration is XCLK position. The PLL is disabled in this position and the oscillator
is provided by X1 external clock.
PLL Enables PLL crystal oscillator (see below)
XCLK Disables PLL crystal oscillator (R1 should be installed) default
To enable PLL clock do the following:
1. Remove R1 on the bottom of the board to isolate the X1 external clock input to the
PLL oscillator.
2. Install user selected Y1, C1 and C2 to provide new oscillator clock.
3. Install RX1, CX1 and CX2 to provide correct XFC conditioning for the frequency of
operation desired. NOTE: see MC68HC912D60 user manual for more information.
4. Move JP1 to the PLL position.
5. Note that the provided firmware utilities (Mon12, NoICE, etc) in External EPROM
will not operate with PLL enabled.