PEB 20560
Description of Registers
Semiconductor Group
5-73
2003-08
transmits the contents of the XFIFO (1…32 bytes) fully transparent
without HDLC-framing, i.e. without flag, CRC-insertion, bit stuffing.
The cyclical transmission continues until the command (CMDR:XRES) is
executed or the bit XREP is reset. The inter frame timefill pattern is issued
afterwards.
When resetting XREP, data transmission is stopped after the next XFIFO-
cycle is completed, the XRES-command terminates data transmission
immediately.
Note: MODE:CFT must be set to ‘0’ when using cyclic transmission.
XPD/XTF
Transmit Prepared Data/Transmit Transparent Frame.
Auto-mode: XPD
Prepares the transmission of an I-frame (“prepared data”) in auto-mode.
The actual transmission starts, when the SACCO receives an I-frame with
poll-bit set and AxH as the first data byte (PBC-command “transmit
prepared data”). Upon the reception of a different poll frame a response
is generated automatically (RR-poll
RR-response, I-poll with first byte
not AxH
I-response).
Non-auto-mode, transparent mode 0,1: XTF
The transmission of the XFIFO contents is started, an opening flag
sequence is automatically added.
Extended transparent mode 0,1: XTF
The transmission of the XFIFO contents is started, no opening flag
sequence is added.
Transmit Direct Data (auto-mode only!).
Prepares the transmission of an I-frame (“direct data”) in auto-mode. The
actual transmission starts, when the SACCO receives a RR-frame with
poll-bit set. Upon the reception of an I-frame with poll-bit set, an I-response
is issued.
Transmit Message End (interrupt mode only).
A ‘1’ indicate that the data block written last to the XFIFO completes the
actual frame. The SACCO can terminate the transmission operation
properly by appending the CRC and the closing flag sequence to the data.
XME is used only in combination with XPD/XTF or XDD.
Note: When using the DMA-mode XME must not be used.
XDD
XME
XRES
Transmit Reset.
The contents of the XFIFO is deleted and IDLE is transmitted. This
command can be used by the CPU to abort a frame currently in
transmission. After setting XRES a XPR-interrupt is generated in every
case.