The Freescale Freedom development board is an evaluation
and development tool ideal for rapid prototyping of
microcontroller-based applications. The hardware design is
form-factor compatible with popular third-party hardware
designed to work with Arduino™ and Arduino-compatible
boards.
The Freescale KL27Z Freedom board (FRDM-KL27Z) is a
simple, yet sophisticated design featuring a Kinetis L series
microcontroller KL27Z, a 3.3V microcontroller built on the
ARM® Cortex®-M0+ core.
The Kinetis L series is the most scalable portfolio of
low-power, robust, mixed signal 32-bit ARM Cortex-M0+
MCUs running up to 48 MHz in the industry. It supports
power supply voltage range from 1.71V to 3.6V, ambient
operating temperature ranges from -40°C to 105°C and
includes up to 64 KB flash.
The FRDM-KL27Z includes the Freescale open standard
embedded serial and debug adapter known as OpenSDA.
This circuit offers the user several options for serial
communications, flash programming and run-control
debugging.
There are also many software development tool options available to the user. Choices include Kinetis
Design Studio (KDS), IAR Embedded Workbench, Keil MDK featuring the µVision IDE, etc.
All of these features combine to give users the freedom needed to rapidly prototype many embedded
designs: a powerful microcontroller built on a very low-power core and SoC platform, easy-access to I/O
with a large ecosystem of compatible hardware, a flexible programming and debug interface, and a large
ecosystem of software development environments.
2Reference documents
•OpenSDA User’s Guide: A guide for users of the OpenSDA embedded circuit
•KL27 Sub-Family Reference Manual: A reference manual for KL27 sub-family devices
•Arduino Overview: A guide to the Arduino platform
•Arduino Uno: A guide to Arduino Uno revision
3Getting started
Refer to the FRDM-KL27Z Quick Start Package for step-by-step instructions for getting started with the
freedom board. See the “Jump Start Your Design” section at freescale.com/FRDM-KL27Z for the Quick Start Package and software lab guides.
4FRDM-KL27Z hardware overview
The FRDM-KL27Z hardware is a Freescale Freedom development board assembled with the following
features:
•Kinetis L series KL27 family MCU MKL27Z64VLH4 in an 64 LQFP package
Figure 1 shows a block diagram of the FRDM-KL27Z board.
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FRDMKL27Z User’s Guide, Rev. 0, 02/2015
Figure 1. FRDM-KL27Z block diagram
FRDM-KL27Z hardware overview
The FRDM-KL27Z features two microcontrollers (MCUs): the target MCU and a serial and debug adapter
(OpenSDA) MCU. The target MCU is a Kinetis series KL27 family device, the KL27Z64VLH4. The
OpenSDA MCU is a Kinetis K series K20 family device, the K20DX128VFM5.
Features of the KL27Z64VLH4 target MCU include:
•32-bit ARM Cortex-M0+ core
— Up to 48 MHz operation
— Single-cycle fast I/O access port
•Memories
— 64 KB flash
— 16 KB SRAM
— 16 KB ROM with build-in bootloader
— 32 bytes regfile
•System integration
— 4-channel DMA controller
— Watchdog
— Low-leakage wakeup unit
— SWD debug interface and Micro Trace Buffer
— Bit Manipulation Engine
•Clocks
— 48 MHz high accuracy internal reference clock
— 8/2 MHz low power internal reference clock
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— 32-40 kHz, or 3-32 MHz crystal oscillator
— 1 kHz LPO clock
•Analog peripherals
— 16-bit SAR ADC with internal voltage reference, up to 17 channels
— High-speed analog comparator containing a 6-bit DAC and programmable reference input
— 1.2 V voltage reference (Vref)
•Communication peripherals
— USB full-speed slave controller supporting crystal-less recovery
— Two 16-bit SPI modules
— One UART module supporting ISO7816
— Two LPUART modules
—Two I2C modules supporting up to 1 Mbit/s
— One FlexIO module
•Timers
— One 6-channel Timer/PWM module
— Two 2-channel Timer/PWM modules
— One low-power timer
— Periodic interrupt timer
— Real-time clock
•Security
— 80-bit unique identification number per chip
•Human-Machine Interfaces (HMI)
— Up to 54 general purpose input/output (GPIO)
— GPIO interrupt
— External input pin for LLWU in LLS and VLLSx mode
5FRDM-KL27Z hardware description
5.1Power supply
The FRDM-KL27Z offers a design with multiple power supply options. It can be powered from the USB
connector, battery on the board, the VIN pin on the I/O header, or an off-board 1.71-3.6V supply from the
3.3V pin on the I/O header. The USB and VIN supplies are regulated on-board using a 3.3V linear
regulator to produce the main power supply. The other two sources are not regulated on-board. Figure 2
shows the schematic drawing for the power supply inputs and the on-board voltage regulator.
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FRDM-KL27Z hardware description
Figure 2. FRDM-KL27Z power supply
Table 1 provides the operational details and requirements for the power supplies.
Table 1. Tower supply requirements
Supply SourceValid Range
OpenSDA USB (J13)5VYesYes
Mini USB(J10)5VNoYes
P5V0-9V0_VIN Pin on I/O header4.3-9VNoYes
P3V3 Pin on I/O header1.71-3.6VNoNo
Battery2-3.6VNoNo
OpenSDA
Operational?
Regulated
On-board?
NOTE
The OpenSDA circuit is only operational when a USB cable is connected
and supplying power to J13. However, the protection circuitry is in place to
allow multiple sources to be powered at once.
Table 2. FRDM-KL27Z power supplies
Power Supply NameDescription
P5V0-9V0_VINPower supplied from the V
P5V_SDAPower supplied from the OpenSDA USB connector (J13).
P5V_KL27ZPower supplied from the Mini USB connector (J10).
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pin of the I/O headers (J3 pin 16).
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Table 2. FRDM-KL27Z power supplies
P3V3_VREGRegulated 3.3V supply. Sources power to the P3V3 supply rail through an optional back drive
protection Schottky diode.
P3V3Main supply rail for the FRDM-KL27Z. Can be sourced from P3V3_VREG.
P3V3_KL27ZKL27Z MCU power supply. Header J17 provides a convenient means for KL27Z energy consumption
measurements.
P3V3_SDAOpenSDA circuit power supply.
NOTES
J9 and J17 are not populated by default. The two pins of these headers are
in parallel with 0 Ω resistors. In addition, J17 is also in parallel with a 10 Ω
resistor. To measure the energy consumption of the KL27Z, either a
voltmeter or an ammeter may be used. To use a voltmeter, R2 (0 Ω) must be
removed before connecting the voltmeter probes to the pins of J17. Both R1
and R2 (10 Ω) must be removed to measure current with an ammeter. For
the OpenSDA MCU, energy consumption can be measured by removing R4
(0 Ω) and connecting ammeter probes to the pins of J9.
5.2Serial and debug adapter (OpenSDA)
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 MCU with 128 KB of embedded flash 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, and more. Two or more OpenSDA applications can run simultaneously. For example, run-control debug application and serial-to-USB converter runs in parallel to provide a virtual COM communication interface while allowing code debugging via OpenSDA with just a
single USB connection. These two applications are provided in a single code package. Refer to the
OpenSDA User’s Guide for more details.
6Freescale Semiconductor, Inc.
Figure 3. OpenSDA block diagram
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FRDM-KL27Z hardware description
OpenSDA is managed by a Kinetis K20 MCU built on the ARM Cortex-M4 core. The OpenSDA circuit
includes a status LED (D8) and a RESET pushbutton (SW2). The pushbutton asserts the Reset signal to
the KL27Z target MCU. It can also be used to place the OpenSDA circuit into Bootloader mode by holding
down the RESET pushbutton while plugging the USB cable to USB connector J13. Once the OpenSDA
enters bootloader mode, other OpenSDA applications such as debug app can be programmed.
SPI and GPIO signals provide an interface to the SWD debug port of the KL27Z. Additionally, signal
connections are available to implement a UART serial channel. The OpenSDA circuit receives power
when the USB connector J13 is plugged into a USB host.
5.3Debugging interface
Signals with SPI and GPIO capability are used to connect directly to the SWD of the KL27Z. These signals
are also brought out to a standard 10-pin (0.05”) Cortex Debug connector (J11) as shown in Figure 4. It is
possible to isolate the KL27Z MCU from the OpenSDA circuit and use J11 to connect to an off-board
MCU. To accomplish this, cut the trace between pin1 and pin2 of J18 on bottom layer. This will disconnect
the SWD_CLK pin to the KL27Z so that it will interfere with the communications to an off-board MCU
connected to J11.
Figure 4. SWD debug connector to KL27Z
5.4Virtual serial port
A serial port connection is available between the OpenSDA MCU and LPUART0 pin PTA1(TXD) and
PTA2 (RXD) of KL27Z. Several of the default OpenSDA Applications provided by Freescale, including
the MSD Flash Programmer and the P&E Debug Application, provide a USB Communications Device
Class (CDC) interface that bridges serial communications between the USB host and this serial interface
on the KL27Z.
5.5Clock source
The Kinetis KL27 microcontrollers feature an on-chip oscillator compatible with input crystal: 32 to 40
KHz or 3 to 32 MHz. The KL27Z on the FRDM-KL27Z is clocked from the internal clock LIRC (2 MHz/8
MHz) or HIRC (48 MHz), and on-board 32768 Hz crystal for the RTC clock source.
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FRDM-KL27Z hardware description
5.6Serial port
The serial port interface signals used with OpenSDA are LPUART0 pin PTA1 (TXD) and PTA2 (RXD).
These signals are also connected to I/O header J1.
5.7Reset
The RESET signal on the KL27Z is connected externally to a pushbutton, SW2. The reset button can be
used to force an external reset event in the target MCU. The reset button can also be used to force the
OpenSDA circuit into bootloader mode when plugging the USB cable to J13. Refer to Section 5.2, “Serial
and debug adapter (OpenSDA)” for more details.
5.8Debug
The sole debug interface on all Kinetis L series devices is a Serial Wire Debug (SWD) port. The primary
controller of this interface on the FRDM-KL27Z is the onboard OpenSDA circuit. However, a 2x5-pin
(0.05”) Cortex Debug connector, J11, provides access to the SWD signals for the KL27Z MCU. Ta ble 3
shows SWD connector signals description for KL27Z.
Table 3. ARM JTAG/SWD mini connector description
PinFunctionConnection to KL27Z
1VTrefP3V3_MCU
2SWDIO/TMSPTA3
3GNDGND
4SWDCLK/TCKPTA0
5GNDGND
6SWO/TDONC
7NCNC
8TDINC
9NCNC
10RESETPTA20
5.9Capacitive touch slider
Two GPIO pins functioning as Touch Sense Input (TSI) signals, are connected to capacitive electrodes
configured as a touch slider as shown in Figure 5.
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Figure 5. Touch slider connection
5.106-axis accelerometer and magnetometer
A Freescale MMA8451Q low-power, three-axis accelerometer is interfaced through an I2C bus and two
GPIO signals as shown in Table 4. By default, the I2C address is 0x1D (SA0 pulled high).
Table 4. Accelerometer signal connections
MMA8451QKL27Z
SCLPTD7
SDA PTD6
INT1PTC3
INT2PTC2
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Figure 6. Accelerometer connection
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FRDM-KL27Z hardware description
This also designed to be compatible with 6-axis (FXOS8700CQ) combination of accelerometer and
magnetometer sensor, if populating the U10 (FXOS8700CQ), and then keep U2 (MAG3310) DNP.
Otherwise, populate U10 (MMA8451) and U2 (MAG3110).
A Freescale MAG3110 low-power, three-axis magnetometer is interfaced through an I2C bus and one
2
GPIO signals as shown in Table 5. By default, the I
Table 5. Magnetometer signal connections
MMA8451QKL27Z
SCLPTD7
SDA PTD6
INT1PTC2
C address is 0x0E .
Figure 7. Magnetometer connection
5.11RGB LED
Three PWM-capable KL27Z signals are connected to a red, green, and blue LED. The signal connections
are shown in Table 6.
Table 6. RGB LED signal connections
RGB LEDKL27Z
Red CathodePTB18
Green CathodePTB19
Blue CathodePTA13
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FRDM-KL27Z hardware description
Figure 8. RGB LED connection
5.12Input/output headers
The MKL27Z64VLH4 MCU is packaged in a 64-pin LQFP. Some pins are utilized by on-board circuitry,
but many are directly connected to one of four I/O headers (J1, J2, J3 and J4).
5.13Arduino compatibility
The I/O headers on the FRDM-KL27Z are arranged to allow compatibility with peripheral boards (known
as shields) that connect to Arduino and Arduino-compatible MCU boards. The pins on the headers share
the same mechanical spacing and placement as the I/O headers on the Arduino Uno Revision 3 board
design. See Figure 9 for compatible signals.
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Figure 9. I/O headers
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Using the FRDM-KL27Z with EEMBC ULPBench
6Using the FRDM-KL27Z with EEMBC ULPBench
The FRDM-KL27Z board supports the EEMBC® ULPBench benchmark. Information on this benchmark,
including a description of what it is and instructions on how to obtain and use the associated
EnergyMonitor hardware and software can be found at EEMBC.org.
The FRDM-KL27Z board can easily be modified to support the EEMBC ULPBench benchmark and the
connection of the EEMBC EnergyMonitor v1.0.
6.1Hardware modifications required for EnergyMonitor
The only board modifications required are to configure the board to measure current and isolate the
OpenSDA MCU (refer to Figure 2).
•Add J17 and remove R1 and R2. This provides a means of powering the KL27 Kinetis MCU with
the EnergyMonitor.
•Add J9 and remove R4 to isolate the OpenSDA MCU Vdd supply.
•Remove R7, R21 and R83 to isolate external current paths.
•Add a single pin header to TP4.
6.2Programming the ULPBench device software
The ULPBench requires that the specific ULPBench profile software be loaded on the target device. This
can be performed by either using the on-board OpenSDA debug/MSD interface, instruction for which can
be found in the OpenSDA User’s Guide, or by means of an external SWD interface (J11 would need to be
populated to use this method). If the default on-board interface is being used then J5, J6, J7, J9 and J17
must be placed while the code is programmed into the KL27 device. The board should be powered by
means of USB connector J3 when programming the KL27. The EnergyMonitor should not be used to
power the board when programming the KL27. These jumpers, along with the USB cable, must be
removed when the EnergyMonitor is running to obtain the correct benchmark score.
6.3Hardware configuration
The KL27 must be isolated from the OpenSDA MCU and any external pull up devices which may draw
additional current. The hardware modifications in Section 6.1, “Hardware modifications required for
EnergyMonitor” must first be made. The following board jumpers must be removed:
•J9 and J17 to isolate the power supply and allow connection of the EnergyMonitor
•J5 to isolate the RESET line from the OpenSDA MCU
•J6 and J7 to isolate the SWD signals from the OpenSDA MCU
•J19 and J22 to isolate several external pull up devices
•J23 and J24 to isolate the I2C signals from the on board sensor devices
•J25 and J26 to isolate the UART signals from the OpenSDA MCU
•J27 and J28 to isolate the interrupt signals from the on board sensor devices
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Revision history
6.4EnergyMonitor connections
The EnergyMonitor Vcc line should be connected to J17 pin2 and the EnergyMonitor GND line should be
connected to TP4.
7Revision history
This table provides a revision history for this document.
Table 7. Revision history
Rev.
number
102/2015Initial public release.
DateSubstantive change(s)
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