peb2255 Infineon Technologies Corporation, peb2255 Datasheet - Page 131

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

5.3.2
The transmit elastic store with a size of max. 2
temporary store for the PCM data to adapt the system clock (SCLKX) to the internally
generated clock for the transmit data, and to re-translate time slot structure used in the
system to that of the line side. Its optimal start position is initiated when programming the
transmit time slot offset values. A difference in the effective data rates of system side and
transmit side may lead to an overflow/underflow of the transmit memory: thus, errors in
data transmission to the remote end may occur. This error condition (transmit slip) is
reported to the microprocessor via interrupt status registers.
The received bit stream from pin XDI is optionally stored in the transmit elastic buffer.
The memory is organized as the receive elastic buffer. Programming of the transmit
buffer size is done by SIC1.XBS1/0 :
• XBS1/0 = 00 : bypass of the transmit elastic buffer
• XBS1/0 = 01 : one frame buffer or 193 bits
• XBS1/0 = 10 : two frame buffer or 386 bits
• XBS1/0 = 11 : short buffer or 96 bits :
The functions of the transmit buffer are:
• Clock adaption between system clock (SCLKX) and internally generated transmit
• Compensation of input wander and jitter.
• Frame alignment between system frame and transmit route frame
Data Sheet
Maximum of wander amplitude (peak-to-peak): (1 UI = 648 ns )
System interface clocking rate: 8.192 MHz:
Max. wander : 80 UI in channel translation mode 0
Max. wander : 50 UI in channel translation mode 1
System interface clocking rate: 1.544 MHz:
max. wander: 74 UI
average delay after performing a slip: 96 bits
System interface clocking rate: 8.192 MHz:
142 UI in channel translation mode 0
78 UI in channel translation mode 1
System interface clocking rate: 1.544 MHz:
max. wander: 126 UI
average delay after performing a slip: 193 bits
System interface clocking rate: 8.192 MHz:
Max. wander : 28 UI in channel translation mode 0; channel translation mode 1 not
supported
System interface clocking rate: 1.544 MHz:
max. wander: 38 UI
average delay after performing a slip: 48 bits
route clock (XCLK).
Transmit Elastic Buffer (T1/J1)
131
193 bit (two frames) serves as a
Functional Description T1/J1
FALC-LH V1.3
PEB 2255
2000-07