This is  a little test board I'm putting together to experiment with the MAX32660 processor and the Lattice UP5K Ultra Plus FPGA.


The UP5K is a tiny FPGA, available in a hand solderable 48 pin, 0.5mm pitch QFN with 5k LUTs, 15k bytes of embedded block RAM and 128k bytes of SPRAM (slowish ram in 32k byte blocks). It has 8 multipliers (16 x 16) and draws a static current of 75uA. They cost pocket money, about £5 a few at a time.


It's a volatile FPGA so it needs something with about 104kbytes of ROM or FLASH to start it up.


The MAX32660 (there's a RoadTest just starting for the eval kit for this) is the baby of Maxim's Darwin series of Cortex M4 micros. It's available in tiny and very tiny 0.5mm or 0.4mm pitch QFN, 4mm or 3mm square. My board uses the 3mm sized part because I couldn't get a quick enough delivery on the 4mm ones. This is a fairly amazing chip, 24 pins, 14 IO, 256k bytes of flash, 96 kbytes RAM, 16k cache, 96MHz ARM Cortex M4 core, some very basic peripherals (SPI, UART, I2C , timer and a proper real time clock). It can be very low power and it cost only £1.16 (10 off).


So for not much more than the cost of a serial flash chip to boot up my FPGA I get a real time clock, some other peripherals and a Cortex M4 core.


The tiny FPGA and processor make a very nice pair.


My test board is 40 pin DIL size (18mm x 51mm) and has debug connectors, power regulator (so it will work from 3.6V -> 9V), high speed oscillator and a crystal for the real time clock.. It has many compromises because it was designed in a hurry and with no other purpose than to check out using this pair of parts together. It makes no attempt at any clever power circuits (these are too end application specific to put on a test board.)


It can be programmed using free tools.


I've ordered 10 boards and if anyone has an interesting idea for playing with one (and will blog about it on E14) I'll give some away. I'm expecting parts in about 2 weeks, so boards doing something in 4 or 5.


Schematic and pcb picture below, comments welcome (but the boards are ordered so no changes now !).


I'll do a BOM later.