Features:
- FPGA ICE40HX1K (1280 logic cells), or ICE40HX4K (7680 logic cells)
- SRAM 64K x 16bits with disable jumper
- All the IO pins of the HX1K FPGA available in connectors (see HX4K details below)
- USB-SERIAL interface CDC-ACM compatible (an FTDI FT232R can be used instead)
- 25xx SPI Flash for configuration. Almost any SOIC-8 chip is OK, (including wider SOIC-8)
- LPC1112 microcontroller for memory uploading, FPGA configuration, and clock generation.
- Clock Frequency: 12 MHz (default) on pin 21. (Other frequencies can be selected via loader)
ICE40HK4X details:
- The HX4K has more IO pins than the HX1K. These extra pins aren't available on the connectors.
- Pin 58 isn't connected in the HX4K.
- The two PLLs of the HX4K are avaliable.
Hardware Sources:
Firmware for the microcontroller & linux uploader:
lpc11loader.tgz folder listing:
lpc11loader- An ARM toolchain is required for firmware compilation.
- Now, the frequency of pin 21 can be selected from the command line. It defaults to 12MHz, but it can also be 16MHz. (or in general 48MHz/N, with N integer)