Datasheet
FRDM-KE02Z40M User’s Guide, Rev. 0, 03/2014
6 Freescale Semiconductor, Inc.
P3V3_VREG
Regulated 3.3 V supply
Sources power to the P3V3 supply rail through a back drive protection
Schottky diode.
P3V3
Main supply rail for the board
Can be sourced from P3V3_VREG, or directly from the I/O headers
(J9 pin 8), or from P3V3_MOTOR.
P3V3_KE02Z
KE02Z MCU power supply
Header J3 provides a convenient means for KE02Z energy
consumption measurements.
P3V3_SDA
OpenSDA circuit power supply
Header J4 provides a convenient means for K20 energy consumption
measurements.
P5V_USB
Nominal 5 V supplied to the I/O headers (J9 pin 10).
Sourced from P5V_SDA supply through a back drive protection
Schottky diode.
P3V3_MOTOR 3.3 V supply from I/O header provided by motor control board
Notes:
1) Headers J3 and J4 are not populated by default on the production version.
The two pins of these headers are shorted together by 0-ohm resistors, R12
and R26 on the PCB. To measure the energy consumption of either the
KE02Z64 or the OpenSDA MCU, the 0-ohm resistor between these pins must
be first cut off. A current probe or a shunt resistor and voltage meter can then
be applied to measure the energy consumption on these rails. When the MCU
current measurement is done with no further need, this 0-ohm resistor can be
soldered on again.
2) To better get ADC accuracy on KE02Z64, it is recommended that the 0-ohm
resistor R13 be soldered on and ensure there is no power supply from
P3V3_MOTOR and P3V3 sourced from I/O headers.
4.2 Serial and Debug Adapter (SDA)
OpenSDA is an open-standard serial and debug adapter. It bridges serial and debug communications
between a USB host and an embedded target processor as shown in Figure 3. The hardware circuit is
based on a Freescale Kinetis K20 family microcontroller (MCU) with 128 KB of embedded flash
memory and an integrated USB controller. OpenSDA features a mass storage device (MSD) bootloader,
which provides a quick and easy mechanism for loading different OpenSDA applications such as flash
programmers, run-control debug interfaces, serial-to-USB converters, among others. Two or more
OpenSDA applications can run simultaneously. For example, run-control debug application and serial-