TWR-K20D72M User’s Manual
Page 12 of 17
3
Jumper Table
There are several jumpers provided for isolation, configuration, and feature selection. Refer to the
following table for details. The default installed jumper settings are shown in bold with asterisks.
Table 4.
TWR-K20D72M Jumper Table
Jumper
Option
Setting
Description
J1
Infrared Transmitter Connection
*ON*
Connect PTD7/CMT_IRO/UART0_TX to IR Transmitter (D1)
OFF
Disconnect PTD7/CMT_IRO/UART0_TX to IR Transmitter (D1)
J2
Enable Micro USB Power
*ON* Enable USB Power control IC U14
OFF Disable USB Power control IC U14
J3
Infrared Receiver Connection
*ON* Connect IRDA output to EBI_AD8/PTC7/CMP0_IN1
OFF Disable IRDA output to EBI_AD8/PTC7/CMP0_IN1
J4
Microphone connection
*ON* Connection Microphone to ADC1_DP0
OFF Disable Microphone to ADC1_DP0
J6
MCU Power selection
*ON* Connect on board VBRD for MCU power supply
OFF
Isolate MCU from power supply (allows for external supply or
power measurements)
J10
JTAG Power Connection
ON
Connect on-board 5V supply to JTAG port (supports powering
board from external JTAG probe)
*OFF*
Disconnect on-board 5V supply from JTAG port
J13
VBAT Power Selection
*1-2*
Connect VBAT to on-board 3.3V supply
2-3
Connect VBAT to the higher voltage between on-board 3.3V
supply or coin-cell supply
J15
OSJTAG Mode Selection
ON
OSJTAG bootloader mode (OSJTAG firmware reprogramming)
*OFF* Debugger mode
J16
Power 5V and VREG IN Selection
*1-2* 5V Power from OSBDM USB powers LDO regulator
*5-6*
VBUS signal on Micro-USB connector J19 connects to
VREGIN to allow standalone USB operation
6-8
VBUS signal from elevator connector connects to VREGIN
to allow USB operation with complete tower kit
J17
Board power selection
1-2
Board power from VOUT_3V3
*3-5* Board power from 3.3V regulator
5-7
Board power from 1.8V regulator
J18
3.3V VOUT Selection
ON
Connect USB 3.3V regulator output to MCU_PWR
*OFF* Disconnect USB 3.3V regulator output to MCU_PWR
J20
USB power IC over-current signal
connection
*ON*
Connect over-current signal on USB power IC MIC-2026 to
PTC8
OFF
Disconnect over-current signal on USB power IC MIC-
2026 to PTC8
J21
Enable Buzzer
*ON* Enable buzzer to EBI_AD11/FTM0_CH3
OFF Disable buzzer to EBI_AD11/FTM0_CH3
