User manual

LPC4357 Developer’s Kit - User’s Guide
Page 49
Copyright 2012 © Embedded Artists AB
5.3 Installing USB Driver
The OEM Base Board contains an USB-to-UART bridge chip (FT232R from FTDI) that connects UART
channel #0 on the LPC4357 to a virtual COM port on the PC/laptop (via USB). This UART channel is
typically used as the console channel for applications. Printf() output can for example be directed to
this UART channel.
A USB driver must be installed on the PC/laptop in order for the virtual COM port to be created. See
FTDI’s installation guides for details how to install the driver for different operating systems:
http://www.ftdichip.com/Support/Documents/InstallGuides.htm
5.4 Program Download
This section describes some basic methods for downloading application code to the LPC4357. Note
that this section does not describe how to create the application code (write the program and compile
it). It is assumed that a binary file exist that represent the application program. This file is often also
called hex-file, which is a file format that Intel created a long time ago. It can also be a pure binary file
(which is typically called a bin-file).
There are four basic methods for program download (the top two methods are the recommended):
- ISP over USB
ISP is short for In-System Programming. The LPC4357 contains a bootloader in ROM that
can be enabled by pulling pin P2_7 low during reset (pulling signal ISP_EN low will pull P2_7
low). With proper bootmode setting (USB0/USB1 booting selected), the application can then
be downloaded over USB #0 or #1. The DFU class is used to download the application, also
called the ‘boot image’.
An application is needed on the PC for downloading the application code. NXP provides this
application called DFUSec, from http://www.lpcware.com/content/project/dfu-download-
programming-utility-and-security-lpcdfusec-tool/.
Using this method, it is possible to load the application into (internal) SRAM or to (internal)
flash memory or (external) spifi flash.
Details about this method are found in sub-section below.
- SWD/JTAG
There are many different SWD/JTAG interfaces on the market. NXP has created LPC-LINK.
Keil has ULINK. IAR/Segger has JLINK. Code Red has Red Probe, etc. There is also
OpenOCD, which is an open source project. Consult the respective manual for the
SWD/JTAG interface used to get instructions how to download a hex/binary file via
SWD/JTAG.
Using this method, the application can be downloaded to (internal) SRAM, to (internal) flash
memory, to (external) NOR flash or (external) spifi flash. Note that the debugger needs
special download functionality in order to download to flash memories (internal or external).
Check the supported functions in the program development environment/IDE that is used.
SWD/JTAG
Note that the LPC4357 MCU is sensitive to ESD on the JTAG port. Observe extra care
around this. Make sure the ground of the JTAG interface is connected to the OEM Base
Board ground before even connecting the JTAG interface. Never have the OEM Board
unpowered while the JTAG pod is powered.
- ISP over UART
ISP is short for In-System Programming. The LPC4357 contains a bootloader in ROM that
can be enabled by pulling pin P2_7 low during reset (pulling signal ISP_EN low will pull P2_7
low). With proper bootmode setting (USART#0/#3 booting selected), the application can then
be downloaded over USART#0 or #3. An application is needed on the PC for downloading the
application code, for example Flash Magic (http://www.flashmagictool.com/).
Note that the LPC4357 OEM board does not support ISP over USART booting due to
pinning conflicts. It was not possible to place the used pins for USART communication on the