FALC
56
PEF 2256 H/E
T1/J1 Registers
User’s Manual
Hardware Description
349
DS1.1, 2003-10-23
If XREP is set together with XTF (write 24H to CMDR), the FALC
56
repeatedly transmits the contents of the XFIFO (1 to 32 bytes) without
HDLC framing fully transparently, i.e. without flag, CRC.
The cyclic transmission is stopped with an SRES command or by
resetting XREP.
Note:During cyclic transmission the XREP-bit has to be set with every
write operation to CMDR.
XRES
Transmitter Reset
The transmit framer and transmit line interface excluding the system
clock generator and the pulse shaper are reset. However the contents
of the control registers is not deleted.
XHF
Transmit HDLC Frame - HDLC Channel 1
After having written up to 32 bytes to the XFIFO, this command
initiates the transmission of a HDLC frame.
XTF
Transmit Transparent Frame - HDLC Channel 1
Initiates the transmission of a transparent frame without HDLC
framing.
XME
Transmit Message End - HDLC Channel 1
Indicates that the data block written last to the transmit FIFO
completes the current frame. The FALC
56 can terminate the
transmission operation properly by appending the CRC and the
closing flag sequence to the data.
SRES
Signaling Transmitter Reset - HDLC Channel 1
The transmitter of the signaling controller is reset. XFIFO is cleared of
any data and an abort sequence (seven 1s) followed by interframe
time fill is transmitted. In response to XRES an XPR interrupt is
generated.
This command can be used by the CPU to abort a frame currently in
transmission.
Note: The maximum time between writing to the CMDR register and
the execution of the command takes 2.5 periods of the current
system data rate. Therefore, if the CPU operates with a very
high clock rate in comparison with the FALC
56's clock, it is
recommended that bit SIS.CEC should be checked before
writing to the CMDR register to avoid any loss of commands.
If SCLKX is used to clock the transmission path, commands to
the HDLC transmitter should only be sent while this clock is