PSB21150HV14XP Lantiq, PSB21150HV14XP Datasheet - Page 135

• Manufacturer Part Number: PSB21150HV14XP
• Manufacturer: Lantiq

Specifications of PSB21150HV14XP

• Number Of Line Interfaces: 1
• Control Interface: HDLC
• Lead Free Status / Rohs Status: Compliant

1. NT 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 IPAC-X 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
• IPAC-X S-transceiver pulls S/G bit to ZERO (’Idle’ state) as soon as n D-bits = ’1’ are
• IPAC-X S-transceiver transmits inverted echo channel (E bits) on the S-bus to block
• Local D-channel source commences with D data transmission on IOM-2 as long as it
• After D-channel data transmission is completed the controller sets the BAC bit to
• IPAC-X S-transceiver transmits non-inverted echo (E = D).
• IPAC-X S-transceiver pulls S/G bit to ONE (’Ready’ state) to block the D-channel
Note: Right after transmission the S/G bit is pulled to ’1’ until n successive D-bits = ’1’
Figure 76
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.
counted on IOM-2 (see note) to allow for further D-channel access.
all connected S-bus terminals (E = D).
receives S/G = “0”.
ONE.
controller on IOM-2.
occur on the IOM-2 interface. As soon as n D-bits = ’1’ are seen, the S/G bit is set
to ’0’ and the IPAC-X D-channel controller 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.
The number n depends on configuration settings (selected priority 8 or 10) and the
condition of the previous transmission, i.e. if an abort was seen (n = 8 or 10,
respectively) or if the last transmission was successful (n = 9 or 11, respectively).
illustrates the signal flow in an intelligent NT.
135
Description of Functional Blocks
PSB/PSF 21150
2003-01-30
IPAC-X