Fastino gateware and software development
- Fastino is a 32 channels, 2 M/s simultaneous, 16 bit DAC
- AD5542ABCPZ
Hardware
Hardware https://github.com/sinara-hw/Fastino/wiki
Link
- Interface: single EEM
- CLK word clock at 250 MHz/7, 1:7 serialization/deserialization, and 3:4 clock duty cycle
- MOSI0 data 250 Mb/s, 125 MHz DDR bit clock
- MOSI1
- MOSI2
- MOSI3
- MOSI4
- MOSI5
- MISO return data at 125/7 Mb/s (TBD)
- Each word (one word clock cycle with 7 bits per lane) is
7*6=42bits. - A frame consists of 14 words.
- A frame contains 14/2+1 marker bits to provide EOF alignment and a 12 bit CRC.
- This leaves 568 bits per frame for
32*16bits DAC data, a 32 bit channel mask, and 24 bits for configuration and return data addressing - On 6 data lanes, this achieves 1.5 Gb/s raw from the FPGA and 1.45 Gb/s net payload (after accounting for framing and checksum).
- The frame period is 392 ns and the DAC data/sample/update rate is therefore 2.55 MS/s.
- There is one slower upstream lane at 125/7 Mb/s providing 7 bits per frame return data. Details TBD
- Similar to well-known video and highspeed/serdes data links
- Link design benefits Grabber HITL testing
- The Link design can be reused for Humpback and Banker where the same FPGA sits on the EEM.
- Link training (bit slip, delay alignment) is automatic
- Checksum protects the data
- Due to the beat between the 7x4 ns word clock and the 21 ns SPI clock, there is a deterministic jitter in the DAC conversion with an amplitude of 7 ns and a period of 3 samples.
Tools
- migen
- misoc
- yosys
- nextpnr
- icestorm
Build
- If using an old nextpnr version, patch migen to use the
heapplacer
python fastino_phy.pyFlash
See https://github.com/quartiq/kasli-i2c
Figure out the aa-bb-cc-dd-ee-ff mac address of the Kasli connected. Otherwise
if you are using a Kasli that was not provisioned using the tools in kasli-i2c,
patch flash_fastino.py to make it find your Kasli. Assuming Fastino is
connected to EEM0:
python flash_fastino.py aa-bb-cc-dd-ee-ff EEM0 write fastino.bin