These are homegrown, so if you're expecting the full Silabs boards with debugger and LCD.. nope, sorry.
I have half a dozen of these boards surplus, if anyone is interested in them:
They have a few minor oopsies: The QFN footprint is the wrong pitch, so they only take QFP chips, and I forgot to use a pullup resistor on the CP2102N/2104 (either fits) VBUS and RST pins - so if you short the 3V3 rail you blow a hole in the UART (ask me how I know) and put 5V on the 3.3V rail. The micro survived, though!
That aside, they have a 3.3V regulator (MIC5353), two RGB LEDs, and two full 8-bit ports broken out, plus P3 (4-bit and the DAC outputs) The LEDs and SW3 are both on P2, so you don't lose pins to them. They take EFM8BB3 or LB1 chips, which have up to four 12-bit DACs and a 12 or 14-bit ADC. Built-in serial bootloader.
If anyone wants them, I'm looking for £2 each partially assembled (USB connector, LDO, passives, and LEDs.. buttons too I guess) plus shipping (75p in the UK, up to about £3.50 outside depending on service).
No UARTs or micros, sorry (I don't want to sell samples and as I'd planned on QFN, I only have two micros in QFP). Silabs provide samples for both (no LB1s in QFP right now though).