Introduction to nanoFIP's functionality
The nanoFIP is an FPGA component implementing the
WorldFIP
protocol that can be used in field devices able to communicate at the
three standard speeds.
The nanoFIP, that is developed as part of the WorldFIP insourcing
project, is designed to be radiation tolerant by
using different single event upset mitigation techniques such as triple
module redundancy and fail-safe state machines. The device is used in
conjunction with a
FIELDRIVE
driver chip and
FIELDTR
insulating transformer, both available from the company
ALSTOM. For implementing a robust reset,
external logic is needed.
To improve the radiation tolerance, the nanoFIP implements a minimal subset of the WorldFIP services:
- No need for a processor to set up data transfers.
- Consumption of one addressed variable.
- Consumption of one broadcast variable.
- Production of one addressed variable.
- Consumed variable size between 1 and 124 bytes.
- Produced variable size between 2 and 124 bytes settable by hardwired pins.
- Fixed variable addresses.
- WorldFIP speed settable to 31.25 kbit/s, 1 Mbit/s or 2.5 Mbit/s.
- Frame delimiters and Frame Checksum (FCS) using the WorldFIP/IEC standard.
- Produced variable uses PDU_TYPE 40h (compact value Protocol Data Unit).
- nanoFIP status (optional) and MPS (Manufacturing Periodical/Aperiodical Services) status sent together with the produced variable.
- Consumed variables are only updated when correct PDU_TYPE, Length and FCS bytes have been received.
- Consumed freshness and significance data available in memory but not treated.
- Produced freshness and significance show data update status.
- Simple interface to variable data
- Variable data transfer over an integrated memory accessible with an 8-bit WISHBONE System-on-Chip interconnection.
- Possibility of stand-alone mode with 16 input and 16 output lines without the need to transfer data to or from memory.
- Separate data valid outputs for each variable (consumed and produced).
- Several reset possibilities
- External reset pin.
- Addressed reset by broadcast consumed variable validated by station address as data.
- Reset output available to external logic.
_More on nanoFIP specification documentation_
E.Gousiou, E.van der Bij, March 2012