Help with LPC2148 "Hello, World" example!

I have recently designed and fabricated a very simple microprocessor card based around an LPC2148. The board only contains power decoupling caps, a 12 MHz crystal coupled to ground with two parallel 36 pF caps, a 32.768 RT crystal coupled to ground through two parallel 22 pF caps, a serial interface on UART0 only using a MAX3232 chip and its caps, and a 3.3V power supply. Reset circuitry is simply a pushbutton that grounds RST in parallel with a 0.1uF debounce, while a 10k pullup keeps the pin high otherwise.

When I use Philips ISP program (V2.2.3), I can query the chip and get back ‘LPC2148’ as well as the serial number so I believe the chip is powered and operating. I can upload using ‘Upload Flash’ with no problems, but ‘Compare Flash’ fails. I have read elsewhere this is a bug.

And here is the problem. I have not been able to get the chip to do anything after I load a hex file. All I am trying to do with this right now is simply spit out, ‘Hello, World!’ constantly from UART0. No input, no RT clock, just serial output. Unfortunately, ARM programing is new to me so I’m now questioning not only hardware but software as well.

Could someone please send me some code to do the above task? Even better, if anyone has a COMPILED flash image that I could use to test the hardware, that would be great. Please include instructions for compiling/loading so that I can rule out my methods!

Any help would be appreciated. Please feel free to suggest any and all tips–I won’t be offended if they are blatantly obvious. I just need this to work!

Thank you!

I was just thinking on my drive back from lunch: do the JTAG pins have to be pulled either high or low to allow a proper boot? Could the currently floating pins be causing the processor to enter a debugging state?

They are only enabled for JTAG if P1.26 is tied to Vss with a bias resistor. What have you done with that pin?

It’s best to just flash an LED when testing new hardware, it’s much easier than trying to get a UART working.

Leon

Leon,

Thanks for the reply! I did get it working this evening: I realized later in the day that I did not place a pullup on the ISP (P0.14) line so the chip was entering ISP upon power up. Now that that has been added, it works fine!

Thank you for you help.

Bob