PEB2256 Datasheet, PDF (340/490 Pages) Infineon Technologies AG – E1/T1/J1 Framer and Line Interface Component for Long and Short Haul Applications

RFT(1:0)
FALC56 V1.2
PEB 2256
T1/J1 Registers
RFIFO Threshold Level - HDLC Channel 1
The size of the accessible part of RFIFO can be determined by
programming these bits. The number of valid bytes after an RPF
interrupt is given in the following table:
RFT1
0
0
1
1
RFT0
0
1
0
1
Size of Accessible Part of RFIFO
32 bytes (reset value)
16 bytes
4 bytes
2 bytes
The value of RFT 1,0 can be changed dynamically
– If reception is not running or
– after the current data block has been read, but before the command
CMDR.RMC is issued (interrupt controlled data transfer).
Note: It is seen that changing the value of RFT1,0 is possible even
during the reception of one frame. The total length of the
received frame can be always read directly in RBCL, RBCH
after an RPF interrupt, except when the threshold is increased
during reception of that frame. The real length can then be
inferred by noting which bit positions in RBCL are reset by an
RMC command (see table below):
RFT1 RFT0
0
0
0
1
1
0
1
1
Bit Positions in RBCL Reset by a
CMDR.RMC Command
RBC(4:0)
RBC(3:0)
RBC(1:0)
RBC0
Data Sheet
340
2002-08-27