SAB 82525
SAB 82526
SAF 82525
SAF 82526
STI … Start Timer
The internal timer is started.
Note: The timer is stopped by rewriting the TIMR register after start.
XTF … Transmit Transparent Frame
Interrupt mode
After having written up to 32 bytes the XFIFO, this command initiates the transmission of a
transparent frame. An opening flag sequence is automatically added to the data by the
HSCX.
DMA mode
After having written the length of the frame to be transmitted to the XBCH, XBCL registers,
this command initiates the data transfer from system memory to HSCX by DMA. Serial data
transmission starts as soon as 32 bytes are stored in the XFIFO.
XIF … Transmit I-Frame (used in auto-mode only!)
Initiates the transmission of an I-frame in auto-mode. Additional to the opening flag
sequence, the address and control field of the frame is automatically added by HSCX.
XME … Transmit Message End (used in interrupt mode only!)
Indicates, that the data block written last to the transmit FIFO completes the actual frame.
The HSCX can terminate the transmission operation properly by appending the CRC and
the closing flag sequence to the data.
In DMA mode, the end of the frame is determined by the transmit byte count in XBCH,
XBCL! This bit must not be set in DMA mode.
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 an XPR interrupt
is generated in every case.
Semiconductor Group
88
SIEMENS [ Siemens Semiconductor Group ]
