pef20320 Infineon Technologies Corporation, pef20320 Datasheet - Page 82

• Manufacturer Part Number: pef20320
• Description: Multichannel Network Interface Controller For Hdlc With 32 Channels
• Manufacturer: Infineon Technologies Corporation

User’s Manual
2. The receiver is always in one of two possible interframe time-fill states:
Figure 43
3. The ‘0’ extraction is also carried out for the last 6 bits before the stopping sequence.
4. The last 16 (CRC = 0) or 32 (CRC = 1) bits of a frame (after extraction of the zero
5. The check is reported in the NOB bit in the last receive descriptor of the frame
6. The check is reported in the LFD bit in the last receive descriptor of the frame.
to be called F and O.
The following diagram explains them.
A change from F to O and from O to F is reported by an IFC interrupt.
insertions are supposed to be the FCS of the remaining bits of the frame. (For the case
of a frame with less than or equal to 16 or 32 bits respectively see discussion of 7).
The FCS is always checked, the check is reported in the CRCO bit of the last receive
descriptor of the frame
CRCO = 1: FCS was incorrect
CRCO = 0: FCS was correct.
NOB = 1:
NOB = 0:
If NOB = 1: The last access to a receive data section of the frame may contain
erroneous bits and shouldn’t be evaluated.
LFD = 1:
LFD = 0:
Only the bytes up to the
are transferred to be stored memory. The bytes of the last access may be erroneous
and shouldn’t be evaluated.
MFL + 1
MFL – 1
MFL – 3
The bit length of the frame was not divisible by 8.
The bit length of the frame was divisible by 8.
The number of bytes was greater than MFL.
The number of bytes was smaller or equal to MFL.
st
rd
st
one for CS = 0, CRC = 0
one for CS =1
one for CS = 0, CRC = 1
011111101111110 or
0111111001111110
in the Data Stream
(2 contiguous Flags
received, Flags with
shared Zeros
supported)
RESET or Receive OFF
82
O
F
Receive Initialize
Channel Command
111111111111111
in the Data Stream
(15 contiguous "1"s
received) or a
Receive Abort Channel
Command during 15
received Bits
ITD04577
Functional Description
PEB 20320
01.2000