Posted on March 14, 2014 at 08:23Hi,
SPIRIT1 is equipped with an automatic framer / de-framer that allow to automatically build the packet to send and get all the information from a packet received (according to a preset configuration).
In SPIRIT1 there are three packet formats:
BASIC,
STack,
WMBUS.
Basically, the
BASIC
is like a generic packet with PREAMBLE | SYNC | LENGTH
| ADDRESS | CONTROL | PAYLOAD | CRC (all the fields are configurable).
The
STack
is similar to the BASIC packet format, but it is used to perform automatic acknowledgement.
The
WMBUS
is based on EN13757 and allow automatic Manchester or 3-out-of-6 data coding and SYNC word according to the submode configured.
In all the three packet formats, the user must configure the fields of the packet (by writing the registers of the SPIRIT1) and put the payload into the TX FIFO. Then, after the packet is received, the user will find the information on the fields of the packet received into the registers of the SPIRIT1 and the payload into the RX FIFO.
The automatic packet handler can be disabled configuring the direct mode. There are two direct modes:
direct mode through FIFO and
direct mode through GPIO. In both the direct mode, the user must build the packet manually into the TX FIFO (or through the GPIO). This means, the user must put the preamble into the TX FIFO, then the SYNC, the payload and so on. Of course the user can build the packet as he likes it, also using a different data coding (the default is the NRZ of course).
Best Regards,
Gaetano
