Serial interface with 3964R protocol
The communication is an asynchronous and a bit
serial transmission method. This means that only one
data stream is generated when data is produced, for
example due to a fingertip. If data is to be sent, they
are provided in the output buffer (TX_BUFFER) and
then forwarded by the interpreter to the protocol. Also
received data in the receive buffer (RX_BUFFER)
is stored and then passed to the interpreter that they
processed. When the transfer is done with a character
length of 8 bits, bit 7 is zero. The control characters
for transmission of the 7- bit code are taken from the
DIN 66003. The following Table 1 shows an overview
of how data with the 3964R protocol is sent.