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PEB 20321
PEF 20321
Host Memory Organization
Data Sheet
283
2001-02-14
12.4
Interrupt Bit Field Definitions
The functions of the interrupt bits depend on the protocol mode. They are therefore
discussed bit by bit, indicating the different meanings in each mode.
R/T:
(all modes)
Determines the direction of the interrupt (
‘
1
’
= Rx,
‘
0
’
= Tx).
FRC:
(V.110/X.30 mode, receive direction only)
Change of the framing (E, S, X) bits of the V.110/X.30 frame detected.
This interrupt is generated whenever a change in the E-, S-, X-bits is
detected, but at most one time within one frame of 10 octets, even if there
is more than one change within the frame. After detecting a receive abort
channel command for one 10-octet frame FRC is also issued.
Ex, Sx, X:
(V.110/X.30 mode, receive direction only, only in conjunction with FRC)
The value of the bits Ex, Sx, X in the received V.110/X.30 frame. If a
value changes e.g., two times within the same frame, only the final
change is reported.
If the change was caused by a receive abort channel command all bits
are 0.
HI:
(all modes, all directions)
Host initiated Interrupt; this bit is set when the MUNICH32X detects the
HI bit in the Rx or Tx descriptor and branches to the next descriptor, or
starts polling the HOLD bit if set.
FI:
1.1 HDLC, TMB, TMR
Receive Direction:
FI = 1 indicates, that a frame has been received completely or was
stopped by a receive abort channel command or fast receive abort or a
HOLD in a Rx descriptor. It is set when the MUNICH32X branches from
the last descriptor belonging to the frame to the first descriptor of a new
frame. It is also set when the descriptor in which the frame finished
contained a HOLD bit, the interrupt is then issued when the MUNICH32X
starts polling the HOLD bit.
1.2 HDLC, TMB, TMR, TMA Transmit Direction:
issued if the FE bit is detected in the Tx descriptor. It is set when the
MUNICH32X branches to the next Tx descriptor, belonging to a new
frame, or when it starts polling the HOLD bit if set in conjunction with the
FE bit; ERR and FI are set if a Tx descriptor contains a HOLD bit, but no
FE bit
IFC:
(HDLC mode, Receive direction only)
Idle/Flag Change; an interrupt is generated in HDLC if the device
changes the interframe time-fill (ITF) state. After reset, the device is in
the ITF idle state. It changes to the ITF flag state if it receives two
consecutive flags with or without shared zeros. It changes back to the ITF