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freescale.comQuick Start Guide
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Jumper Option Setting Description
J8 MCU Power
Connection
ON Connect on-board 3.3 V supply to MCU
OFF Isolate MCU from power
(connect an ammeter to measure current)
J20 MCU VDD_INT Power
Connection
ON Connect VDD and VDD_INT rails together
OFF Isolate MCU VDD_INT from power
(connect an ammeter to measure current)
J17 VBAT Power Selection 1-2 Connect VBAT to on-board 3.3 V supply
2-3 Connect VBAT to the higher voltage between
onboard 3.3 V supply or coin-cell supply
J18 Oscillator output enable OFF 50 MHz oscillator output enabled
ON 50 MHz oscillator output disabled
J10 OSJTAG Bootloader
Selection
ON OSJTAG bootloader mode
(OSJTAG firmware reprogramming)
OFF Debugger mode
Jumper Option Setting Description
J19 50 MHz Oscillator
Power
ON ON = onboard 50 MHz oscillator powered
OFF OFF = onboard 50 MHz oscillator not powered*
J12 JTAG Board Power
Connection
ON Connect onboard 5 V supply to JTAG port
(supports powering board from JTAG pod
supporting 5 V supply output)
OFF Disconnect onboard 5 V supply to JTAG port
J2 IR Transmitter
Connection
ON Connect PTD7/CMT_IRO to IR transmitter (D1)
OFF Disconnect PTD7/CMT_IRO from IR transmitter (D1)
J16 IR Receiver Connection ON Connect DAC1_OUT/CMP2_IN3 to IR receiver
OFF Disconnect DAC1_OUT/CMP2_IN3 from IR receiver
J1 VREGIN Power
Connection
ON Connect USB0_VBUS from elevator to VREGIN
OFF Disconnect USB0_VBUS from elevator to VREGIN
TWR-K70F120M Jumper Options
The following is a list of all the jumper options. The default installed jumper settings are
indicated in the shaded boxes.
*NOTE: This option must be selected whenever a Tower System module card that provides a clock on primary
elevator pin B24 is connected to the CPU module.