This OM13042 development board has been developed by NXP in cooperation with ON Semiconductor and Weinzierl Engineering and is available at NXP Distributors.

Building automation systems based on KNX communication protocols

Introduction

The following formula may be used to calculate a parallel resonant crystal's external load capacitors:
CL = ((CX1 x CX2) / (CX1 + CX2)) + Cstray
where:
CL = the crystal load capacitance
Cstray = the stray capacitance in the oscillator circuit, which will normally be in the 2pF to 5pF range.

Assuming that CX1=CX2 then the equation becomes:
CL = ((CX1 x CX1) / (2 x CX1)) + Cstray
CL = (CX1 / 2) + Cstray
Rearranging the equation, we can find the external load capacitor value:
CX1 = 2(CL - Cstray)

For example, if the crystal load capacitance is 15pF, and assuming Cstray=2pF, then:

Yes. In case of a software reset like WD reset, BOD reset etc, the SRAM contents (memory address 0x1000 0000 to 0x1000 2000 in case of LPC1227 ) is retained. However, the part won't retain the contents if it goes to deep power-down mode or if the microcontrollers is unpowered.

To place code in RAM, follow the link here:

http://support.code-red-tech.com/CodeRedWiki/CodeInRam

The IO pin will be 5V tolerant if the supply voltage Vdd is present, and they are configured as inputs. VDDIO must be applied to the microcontroller when input voltage is 5V, or else the 5V tolerance does not apply.

The LPCXpresso forum is a great place to start. The forum is found at http://knowledgebase.nxp.com/lpcxpresso.php
You can also find code examples at http://ics.nxp.com/support/lpcxpresso/

The LPCXpresso IDE is available for Windows, Linux and Mac OS X hosts. LPCXpresso can be downloaded from http://lpcxpresso.code-red-tech.com/LPCXpresso/.

LPCOpen release history

The LPCOpen versioned releases are shown below. The LPCOpen software download page contains the latest of LPCOpen. Older versions of the platform can be found on this page. The changes for each version, as wells as known issues for each release, are included on this page. For upcoming LPCOpen releases, go here.