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PEB 20321
PEF 20321
Detailed Protocol Description
Data Sheet
113
2001-02-14
Options
The different options for this mode are
–
The value of the fill-character can be programmed for FA = 1 in the channel
specification. The fill-character (TC) is then programmed in the TFLAG. For FA = 0 the
fill character is FF
H
and TFLAG has to be set to 00
H
. If subchanneling is chosen (not
all fill/mask bits of the channel are
‘
1
’
) FA must be set to
‘
0
’
.
–
The number of inter-data time-fill characters as shown in
Figure 23
.
By setting the value of FNUM the following sequences result:
FNUM = 0
…
DATA 1, TC, DATA 2
…
FNUM = 1
…
DATA 1, TC, TC, DATA 2
…
FNUM = 2
…
DATA 1, TC, TC, TC, DATA 2
…
–
DATA 2 starts at synchronization pulse TSP;
‘
1
’
are sent between last TC and
DATA 2.
–
In case of using subchanneling by fill masks the MUNICH32X supports two different
modes of operation in Transparent Mode A (TMA). These modes are selected by bit
'CRC' in the channel configuration.
CRC =
‘
0
’
:
Data is transmitted transparently only in bit positions selected by the transmit fill mask
(corresponding fill mask bit equal
‘
1
’
). Masked bit positions are driven Tristate
‘
Z
’
. In
receive direction bits are received from bit positions selected by the receive fill mask
(corresponding fill mask bit equal
‘
1
’
) only. Receive data is grouped to octets and
stored in memory transparently (no gaps).
CRC =
‘
1
’
:
In transmit direction each data octet is masked with the transmit fill mask. Masked bit
positions are overwritten with Tristate
‘
Z
’
when transmitted. In receive direction the
receive fill mask has to be set to 0xFF. The entire 8 bit time slot is received and stored
byte aligned in memory. It is the software responsibility to mask received data octets
as needed by the application.