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PEB 20321
PEF 20321
Host Memory Organization
Data Sheet
294
2001-02-14
frame. An interrupt with FI, ERR is issued. For V.110/X.30 and TMA data bits might
get lost. An interrupt with ERR is issued.
–
Receive Off
(not supported by LBI)
RI =
‘
0
’
, RO =
‘
1
’
, R =
‘
0
’
(clears a previous receive abort condition, sets off condition,
affects only the serial interface)
This channel command sets the receiver into the receive off condition. The receive
channel is disabled completely at the serial interface, i.e. the receive deformatter RD
is reset and the receive buffer RB is not accessed for this channel. A currently
processed frame (HDLC, TMB, TMR mode) is not properly finished with any status
information. The data stored in the RB at that time is still transferred to host memory.
After the receive off condition is cleared by another channel command:
in HDLC, TMB, TMR (V.110/X.30, TMA) mode the device waits for a new frame (10-
octet frame, nothing) to begin and then starts filling RB again. If the receive off
command lead to an improper finishing of a frame (data, data), the new frame (data,
data) is concatenated with the finished one. To avoid this problem there are two
suggestions:
a) issue a receive abort channel command and wait for 32 (240, 8) bits for this
channel to be processed before issuing the receive off command.
b) wait in the receive off condition until the RB is emptied for this channel (i.e. for at
most 8 PCM frames if the MUNICH32X has sufficient access to the shared
memory) and leave the receive off condition by a receive initialization command.
The receive off channel command is ignored in case of any kind of loop.
–
Receive Abort
(not supported by LBI)
RI =
‘
0
’
, RO =
‘
1
’
, RA =
‘
1
’
(clears a previous receive off condition, sets a receive abort
condition, affects only the serial interface)
This receive channel command sets the receiver into the receive abort condition. In
this condition it receives (instead of the normally received bits)
logical
‘
1
’
bits for HDLC
logical
‘
0
’
bits for V.110/X.30, TMB, TMR
logical
‘
0
’
bits for TMA mode
irrespective of the INV bit.
This leads to
For HDLC: a currently processed frame is aborted after
≤
7 received bits for this
channel, leading to a RA set in the status of the frame and an interrupt with set FI
and ERR bits only or to an interrupt with set SF, FI and ERR bits. If the receiver was
in the flag interframe time-fill state it will lead to an interrupt with set IFC bit after
≤
15 received bits.
For V.110/X.30: if the receiver was in the synchronized frame state it will go to the
unsynchronized state after
≤
240 bits and issue a LOSS bit in the status of the
current Rx descriptor. It will also issue an interrupt with set ERR bit and (unless all
E-, S-, X-bits were
‘
0
’
previously) issue one or two interrupts with FRC set and having
all E-, S-, X-bits at
‘
0
’
in the last one.