UM11121 LPCXpresso51U68 Rev 1.
UMxxxxx NXP Semiconductors LPCXpresso51U68 Revision history Rev Date Description 1.0 20180112 Initial version 1.1 20180427 First release version Contact information For more information, please visit: http://www.nxp.com UM11121 User manual All information provided in this document is subject to legal disclaimers. Rev 1.1 — 27 April 27, 2018 © NXP Semiconductors N.V. 2018. All rights reserved.
UM11121 NXP Semiconductors LPCXpresso51U68 1. Introduction The LPCXpresso™ family of boards provides a powerful and flexible development system for NXP's Cortex®-M family of MCUs. They can be used with a wide range of development tools, including the NXP’s MCUXpresso IDE. The LPCXpresso51U68 board has been developed by NXP to enable evaluation of and prototyping with the LPC51U68 MCUs, and is based on the LPC51U68JBD64 version of the MCU. Fig 1.
UM11121 NXP Semiconductors LPCXpresso51U68 2. Feature summary The LPCXpresso51U68 board includes the following features: • On-board, high-speed USB based, Link2 debug probe with ARM’s CMSIS-DAP and SEGGER J-Link protocol options. • Link2 probe can be used with on-board LPC51U68 or external target. • Support for external debug probes. • Tri-color LED. • Target Reset, ISP, and WAKE buttons. • Expansion options based on Arduino UNO and PMod™, plus additional expansion port pins. • On-board 1.8/3.
UM11121 NXP Semiconductors LPCXpresso51U68 Fig 2. LPCXpresso51U68 layout The function of each identified component is listed in Table 1. Table 1. Table Board interface components Circuit ref Description Ref section D1 Link2 LPC43xx BOOT0_LED indicator. Reflects the state of LPC43xx Link2 MCU P1_1. When the boot process fails, D1 will toggle at a 1 Hz rate for 60 seconds. After 60 seconds, the LPC43xx is reset. 7 D2 Tri-color LED driven by Target LPC51U68 MCU. JP8 must be shunted for +3.
UM11121 NXP Semiconductors LPCXpresso51U68 Circuit ref Description J5 Target MCU Power / USB Device connector. Connect this micro USB B-type 6 connector to a +5V power source when it is desired to power only the Target MCU, and leave the on-board Link2 debug probe unpowered. J6 Link2 micro USB B-type connector. Powers both the Link2 side of the board and LPC51U68 Target side of the board. Power the board from this connector when using the on-board debug probe to debug the LPC51U68 Target MCU.
UM11121 NXP Semiconductors LPCXpresso51U68 Circuit ref P3 P4 SW1 SW2, SW3 Description Ref section negative. LPC51U68 current is calculated by dividing the measured voltage at P2 by the Vsense resistance value of 4.12Ω. FTDI serial header. In addition to provide a serial output from LPC51U68, the Target side of the board can be powered from the FTDI header. The LPC51U68 supports serial ISP boot from the FTDI header. External ADC reference input.
UM11121 NXP Semiconductors LPCXpresso51U68 3. Getting Started By default, the LPCXpresso51U68 is configured to use the on-board debug probe (Link2) to debug the on-board target (LPC51U68), using the CMSIS-DAP debug protocol preprogrammed into the Link2 Flash memory. The MCUXpresso IDE (available for free download at http://www.nxp.com/mcuxpressoide) or development tools that support the CMSIS-DAP protocol can be used in the default configuration.
UM11121 NXP Semiconductors LPCXpresso51U68 6. Allow about 10 seconds for the LPCXpresso51U68 devices to enumerate for the first time; the device will appear as “LPC Device”. 7. If the first attempt to debug a project fails in the IDE, cancel the debug session and repower the board. On some machines the drivers take longer to enumerate for the first time, so these steps should correct this issue. The board is now ready to be used with the MCUXpresso SDK examples for LPCXpresso51U68.
UM11121 NXP Semiconductors LPCXpresso51U68 3.2 Starting a debug session using an external Debug Probe Code running on the LPC51U68 target can be debugged using an external Debug Probe that conforms to the standard ARM debug connector. To use an external Debug Probe connect the probe to the SWD connector (P1) and connect power via the micro USB connector J5.
UM11121 NXP Semiconductors LPCXpresso51U68 1 2 3 4 5 6 Fig 3. Table 2. FTDI connector P3 FTDI interface LPC51U68 Signal FTDI signal Pin # Direction LPC51U68 Signal GND GND 1 GND No connect CTS 2 No connect Board +5V 5V 3 Board +5V UART0_RXD TXD 4 From host UART0_RXD UART0_TXD RXD 5 To host UART0_TXD No connect RTS 6 GND 5.
UM11121 NXP Semiconductors LPCXpresso51U68 The LPC51U68 Target VDD selection of 1.8V or 3.3V is made at JP9, with 3.3V set as the default. Fig 4. Board power diagram 5.1 LPCXpresso51U68 current measurement The LPC51U68 current can be measured by measuring the voltage across a sense resistor in series with the supply, a current meter or using the on board current measurement circuit. Each of these methods will be described in subsections below.
UM11121 NXP Semiconductors LPCXpresso51U68 LPC51U68 Vsense resistor current measurement The voltage across a series 4.12Ω resistor with the target LPC51U68 VDD can be manually measured at P2 on the PCB. The voltmeter positive probe is applied to P2 pin 1 (square pad) and negative probe to P2 pin 2. Use Ohm’s law to calculate the current (LPC51U68 current = measured voltage / 4.12Ω). As an example, if the measured voltage is 10mV, then 10e-3 / 4.12Ω = 2.44mA.
UM11121 NXP Semiconductors LPCXpresso51U68 % Error LPC51U68 current (µA) Fig 5. Current measurement circuit error Shield board current measurement To use the on-board current measurement circuitry, any expansion board must match the functionality of the LPCXpresso51U68. Refer to the board schematics for more information. 6. Debug Configurations The LPCXpresso51U68 LQFP board has a built-in debug probe referred to as “Link2”.
UM11121 NXP Semiconductors LPCXpresso51U68 Debugging LPC51U68 target using on-board (Link2) debug probe To use the on-board Link debug probe, the LPCXpresso51U68 board must be powered from the Link2 USB connector J6, and jumper JP2 must be fitted in position pin 1 - 2 (Local Target). Jumper JP1 must be open to enable the target LPC51U68. Connecting the micro USB J6 to a host computer will power the Link and Target sections of the board and provide the USB link to the debug tool software.
UM11121 NXP Semiconductors LPCXpresso51U68 7. LED indicators The LPCXpresso51U68 board LED locations are shown in Fig 2. A description of each on-board LED indicator is shown in Table 3. Table 3. LED indicator functions LED reference Description D1 Link2 MCU BOOT0_LED indicator. Reflects the state of Link2 MCU P1_1. When the boot process fails, D1 will toggle at a 1 Hz rate for 60 seconds. After 60 seconds, the Link2 MCU is reset.
UM11121 NXP Semiconductors LPCXpresso51U68 Table 4. Expansion connectors Reference Description J1 The odd number pins are compatible with Arduino Uno rev3 Digital 15:8, AREF, SDA & SCL connector. The even numbered pins are used for external access and expansion of LPC51U68 signals not used by the Arduino Uno rev3 compatible interface. J2 The odd numbered pins 1 – 13 are compatible with Arduino Uno rev3 Digital 7:0 connector.
UM11121 NXP Semiconductors LPCXpresso51U68 To force entry into one of these boot modes hold down the required button(s), press and release the Reset button, then release the ISP button(s). Note that for USB Mass Storage boot to work, a USB host must be connected to J5 and JP10 must be installed in order to route Vbus to the LPC51U68. When the LPC51U68 has been booted in mass storage mode a firmware image (which must be named firmware.
UMxxxxx NXP Semiconductors LPCXpresso51U68 10. Legal information provide appropriate design and operating safeguards to minimize the risks associated with their applications and products. 10.1 Disclaimers Limited warranty and liability — Information in this document is believed to be accurate and reliable.
UMxxxxx NXP Semiconductors LPCXpresso51U68 11. List of figures Fig 1. Fig 2. Fig 3. Fig 4. Fig 5. LPCXpresso51U68 Board ................................. 3 LPCXpresso51U68 layout ................................. 5 FTDI connector ............................................... 11 Board power diagram ...................................... 12 Current measurement circuit error .................. 14 UM11121 User manual All information provided in this document is subject to legal disclaimers. Rev 1.
UM10973 NXP Semiconductors LPCXpresso51U68 12. List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table Board interface components ................... 5 P3 FTDI interface ............................................ 11 LED indicator functions ................................... 16 Expansion connectors ..................................... 17 ISP boot mode control ....................................
UM10973 NXP Semiconductors LPCXpresso51U68 13. Contents 1. 2. 2.1 3. 3.1 3.2 4. 4.1 5. 5.1 6. 6.2 7. 8. 9. 9.1 9.2 9.3 10. Introduction ......................................................... 3 Feature summary ................................................ 4 Board layout and settings ................................... 4 Getting Started .................................................... 8 Starting a debug session using the on-board (Link2) Debug Probe ..........................................
