PEF82912FV1.4 Infineon Technologies, PEF82912FV1.4 Datasheet - Page 72

• Manufacturer Part Number: PEF82912FV1.4
• Description: ISDN Interface ISDN
• Manufacturer: Infineon Technologies

Specifications of PEF82912FV1.4

• Mounting Style: SMD/SMT
• Package / Case: MQFP-64
• Lead Free Status / Rohs Status: Details

1. Local D-Channel Controller Transmits Upstream
In the initial state (’Ready’ state) neither the local D-channel sources nor any of the
terminals connected to the S-bus transmit in the D-channel.
The Q-SMINT I S-transceiver thus receives BAC = “1” (IOM -2 DU line) and transmits
S/G = “1” (IOM -2 DD line). The access will then be established according to the
following procedure:
• Local D-channel source verifies that BAC bit is set to ONE (currently no bus access).
• Local D-channel source issues TIC bus address and verifies that no controller with
• Local D-channel source issues BAC = “0” to block other sources on IOM -2 and to
• Q-SMINT I S-transceiver pulls S/G bit to ZERO (’Local Access’ state) as soon as
• Local D-channel source commences with D data transmission on IOM -2 as long as
• After D-channel data transmission is completed the controller sets the BAC bit to
• Q-SMINT I S-transceiver transmits non-inverted echo (E = D).
• Q-SMINT I S-transceiver pulls S/G bit to ONE (’Ready’ state) to block the D-channel
Note: If right after D-data transmission the D-channel arbiter goes to state ’Ready’ and
2. Terminal Transmits D-Channel Data Upstream
The initial state is identical to that described in the last paragraph. When one of the
connected S-bus terminals needs to transmit in the D-channel, access is established
according to the following procedure:
• S-transceiver recognizes that the D-channel on the S-bus is active via D = ’0’.
• S-transceiver transfers S-bus D-channel data transparently through to the upstream
Data Sheet
higher priority requests transmission (TIC bus access must always be performed even
if no other D-channel sources are connected to IOM -2).
announce D-channel access.
CNT
Q-SMINT I S-transceiver transmits inverted echo channel (E bits) on the S-bus to
block all connected S-bus terminals (E = D).
it receives S/G = “0”.
ONE.
controller on IOM -2.
IOM -2 bus.
the local D-channel source wants to transmit again, then it may happen that the
leading ’0’ of the start flag is written into the D-channel before the D-channel
source recognizes that the S/G bit is pulled to ’1’ and stops transmission. In order
to prevent unintended transitions to state ’S-Access’, the additional condition CNT
source may start transmission again (if TIC bus is occupied). This allows an equal
access for D-channel sources on IOM -2 and on the S interface.
2 is introduced. As soon as CNT
n (see note) to allow sending D-channel data from the entitled source.
58
n, the S/G bit is set to ’0’ and the D-channel
Functional Description
PEF 82912/82913
2001-03-30