peb2255 Infineon Technologies Corporation, peb2255 Datasheet - Page 172

• Manufacturer Part Number: peb2255
• Description: E1/t1/j1 Framer And Line Interface Component For Long And Short Haul Applications
• Manufacturer: Infineon Technologies Corporation

8.3
8.3.1
The closing Flag of a previously transmitted frame simultaneously becomes the opening
Flag of the following frame if there is one to be transmitted. The Shared Flag feature is
enabled by setting bit SFLG in control register CCR1.
8.3.2
If enabled via register CCR3, a programmable 8-bit pattern (defined by register PRE) is
transmitted with a selectable number of repetitions after Interframe Timefill transmission
is stopped and a new frame is ready to be sent.
Zero bit insertion is disabled during preamble transmission. To guarantee correct
function the programmed preamble value should be different to the Receive Address
Byte values. Otherwise the preamble could be detected as valid address with shared
flags.
In BOM mode the MSB of the preamble should be reset in order to achieve a faster
synchronization at the BOM receiver. After the preamble has been sent, the transmitter
inserts one sync byte (FF
FIFO.
8.3.3
When programmed in the extended transparent mode via the MODE register
(MDS2...0 = 111), the FALC
HDLC framing, i.e. without
• FLAG deletion
• CRC checking
• Bit-stuffing
In order to enable fully transparent data reception, bit MODE.HRAC has to be set and
FF
Received data is always shifted into RFIFO.
Data transmission is always performed out of XFIFO by shifting the contents of XFIFO
directly into the outgoing data stream. Transmission is initiated by setting CMDR.XTF. A
sync byte FF
8.3.4
If the extended transparent mode is selected, the FALC
transmission of the contents of the transmit FIFO.
Data Sheet
H
has to be written to RAH2.
Signaling Controller Functions
Shared Flags
Preamble Transmission
Transparent Transmission and Reception
Cyclic Transmission (fully transparent)
H
is automatically sent before the first byte of the XFIFO is transmitted.
H
) automatically before sending the contents of the transmit
®
-LH performs fully transparent data reception without
172
Signaling Controller Operating Modes
®
-LH supports the continuous
FALC-LH V1.3
PEB 2255
2000-07