Functional Description
Further Criteria Leading to a Re-Establishment
Q.921 § 5.7.1: Criteria for Re-Establishment
§ 5.7.1 Criteria for re-establishment
The criteria for re-establishing the multiple frame mode of operation are defined in this section
by the following conditions:
a) The receipt while in the multiple frame mode of operation, of an SABME;
b) The receipt of a DL-ESTABLISH-REQUEST primitive from layer 3 (see § 5.5.1.1);
c) The occurrence of N200 re-transmission failures while in the timer recovery condition
(see § 5.6.7)
d) The occurrence of a frame rejection condition as identified in § 5.8.5;
e) On the receipt, while in the multiple frame mode of operation of an FRMR response frame
(see § 5.8.6);
f) The receipt, while in the multiple frame mode of operation, of an unsolicited DM response
with the F bit set to O (see § 5.8.7);
g) The receipt while in the timer recovery condition, of a DM response with the F bit set to 1.
Reaction of the ISAC-S
a) after having checked for validity and non-occurrence of a frame rejection condition, the
error free SABME can be identified after RME-Interrupt by reading the RHCR-register; the
multiple frame est/timer recovery discrimination can be done by reading STAR2: TREC
b) –
c) A TIN-Interrupt occurs (of course MODE: TMD has to have been 1)
d) see section 3
e) see a)
f) see a)
g) see a).
Necessary Software Reactions
The same actions as in section 3 have to be taken. In addition, in case of a) the necessary
discrimination for the software is possible by reading STAR2: WFA while still in auto-mode. If
WFA = 1 then V(S) > V(A); if WFA = 0, then V(S) = V(A).
Semiconductor Group
129
INFINEON [ Infineon ]
