Pin numbering on LPC2148
In the top left corner in the diagram below you will see a circle shown. This is adjacent to pin 1 and pin 64.



In your photo you will see a corresponding dot in the IC in the left lower corner, plus a white dot on the pCB. Both indicate pin 1. ie the IC has been rotated -90 degrees = 90 degrees anticlockwise from datasheet to PCB in this viw.

The dot or indent on the IC, or sometimes a truncated corner on the package, is a common way of indicating wherepin 1 is.



A method finding this outyourself would be to use a continuity tester with beeper, as found in many multimeters, or a meter set to low ohms, place one probe to PCB ground and then run the other probe along the IC pins to find the ground connections. PCB ground is almost certainly on power supply -ve and very probably on the anchoring pad connections for the two crystals and probably on the large UART &amp; USB jacks connections IF these are all common. (eg UART and USB may have signal pins underneath or these may be the signal pins depending on the jack.

Note that when using a continuity tester or low ohms range the meter's inter- probe open circuit voltage MAY exceed the IC's absolute maximum voltage rating - eg it may be at 9V depending in the meter. This is extremely unlikely to cause damage in such cases BUT if it did you would be responsible. Some multimeters use two or three x AA batteries and have a correspondingly lower inter probe voltage. If you have a 9V meter and really care about the probe voltage you could use a zener diode or resistor to load it down somewhat and then note what happens when you short the probes to eg ground.