8
Quick Start Guide
Jumper
Option
Setting
Description
J28
3.3V regulator
input selection
1-2
5V from OpenSDA USB/TWR 5V (P5V_TRG_SDA)
3-5 & 2-4 5V power from on-board USB connector (J23)
J27
MCU power
selection
3-4
3.3V from regulator
1-3
VOUT_3V3 (from MCU)
3-5
1.8V from regulator
J27
Rechargeable
battery
selection
6-8
Rechargeable battery powers input to 3.3V regulator
4-6
Rechargeable battery powers input to 1.8V regulator
J30
MCU VDD
current
measurement
ON
Connect V_BRD to MCU_PWR
OFF
Allow current measurement on MCU VDD
J29
VDDA and
VREFH power
ON
Connect V_BRD to VDDA and VREFH
OFF
Disconnect V_BRD from VDDA and VREF
J17
VBAT power
1-2
Connect VBAT to MCU_PWR
2-3
Connect VBAT to the higher voltage between MCU_PWR and
coin-cell battery (P3V0_COINCELL)
J3
LED
connections
1-2
Connect PTD4 to Yellow LED (D7)
3-4
Connect PTD5 to Red LED (D4)
5-6
Connect PTD6 to Orange LED (D3)
7-8
Connect PTD7 to Yellow/Green LED (D2)
TWR-K24F120M Jumper Options
(continued)
