SAB 82525
SAB 82526
SAF 82525
SAF 82526
Transmit Byte Count High (WRITE)
Value after RESET: 000xxxxx
7
3
0
XBCH
DMA NRM CAS
XC
XBC11
XBC8
(2D/6D)
DMA … DMA Mode
Selects the data transfer mode of HSCX to system memory.
0 … Interrupt controlled data transfer (interrupt mode)
1 … DMA controlled data transfer (DMA Mode)
NRM … Normal Response Mode
Valid in auto-mode only! Use in auto-mode only; reset this bit in non auto-mode, transparent
mode, and extended transparent mode.
Determines the function of the LAP controller:
0 … full-duplex LAPB/LAPD operation
1 … half-duplex NRM operation
CAS … Carrier Detect Auto Start
When set, a high at the CD (A × CLK) pin enables the respective receiver and data reception
is started.
Note: CAS has to be "0" for clock mode 1 and 5
XC … Transmit Continuously
Only valid if DMA mode is selected!
If the XC bit is set, the HSCX continuously requests for transmit data ignoring the transmit
byte count programmed via XBCH, XBCL.
XBC11 … XBC8 … Transmit Byte Count (most significant bits)
Valid only if DMA mode is selected!
Together with XBC7 … XBC0 the length of the frame to be programmed.
Semiconductor Group
102
SIEMENS [ Siemens Semiconductor Group ]
