pef20320 Infineon Technologies Corporation, pef20320 Datasheet - Page 93

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

TMB
Receive Direction
General Features
1. The starting and ending flag (00
2. The number of bits within a frame is checked to be divisible by 8.
3. The number of bytes within a frame is checked to be smaller than MFL + 1.
4. A frame containing less than 8 bits may be ignored completely by the receiver.
More detailed description of the individual features:
1. a. A frame is supposed to have started if after a sequence ‘0000 0000’ a ‘1’-bit is
In both cases the last bit before the sequence 00
frame.
2. The check is reported in the NOB bit in the last receive descriptor of the frame.
3. The check is reported in the LFD bit in the last receive descriptor of the frame.
Options
There are no options in receive direction for this mode.
User’s Manual
fill is recognized and extracted.
b. A frame is supposed to have stopped if
NOB = 1: The bit length of the frame was not divisible by 8.
NOB = 0: The bit length of the frame was divisible by 8.
LFD = 1: The number of bytes was greater than MFL.
LFD = 0: The number of bytes was smaller or equal to MFL.
Only the bytes up to the MFl + 1
of the last access to the receive data section of the frame may contain erroneous bits
and shouldn’t be evaluated. LFD is always accompanied by NOB.
recognized. The frame is supposed to have this ‘1’-bit as first bit.
– either a sequence 0000 0000 1 is found in the data stream after the frame has
– or a sequence 0000 0000 is found octet synchronous (i.e. the first bit of the
started
sequence 00
H
is the 8 m + 1
st
H
st
one are transferred to the shared memory. The bytes
before and after a frame) as well as interframe time-
bit since the starting ‘1’-bit of 1.a. for an integer m).
93
H
is supposed to be the last bit of the
Functional Description
PEB 20320
01.2000