I got my jlink working with a Keil MCB2300 dev board, using the Sourcery lite toolchain today, and was thinking about integrating that with my 030 PDS card.
One topic has been level shifting. The 030 PDS is 5V. The LPC2378 has 5V tolerant IOs, but that's only for input. For output, it's driving 3.3V, which will mostly work, but sometimes might not, and I really don't need to be debugging phantom issues like that. So, level shifting 3.3V output of the LPC2378 to the 5V of the 030 PDS.
I came across the 74HCT244, which seems to be pretty ideal. It's a tristate line driver, so it has the added advantage of tristating the data lines instead of consuming MCU cycles to change the GPIO lines to inputs when not addressed. The 74HC*T* is TTL compatible, so works with 3.3V inputs. It also has a /OE line to toggle the high impedance state of the entire chip, which could be driven by the address decoding logic. Or toggled by the MCU, if necessary.
Or even better, I've come across this for bidirectional communication: SN74LVC8T245
It looks pretty much designed for this task, although not available in DIP.