DS33R41 Maxim Integrated Products, DS33R41 Datasheet - Page 111

• Manufacturer Part Number: DS33R41
• Description: Network Controller & Processor ICs Inverse-Multiplexing Ethernet Mapper wit
• Manufacturer: Maxim Integrated Products

DS33R41 Inverse-Multiplexing Ethernet Mapper with Quad Integrated T1/E1/J1 Transceivers
11
INTERLEAVED PCM BUS OPERATION
In many architectures, the PCM outputs of individual framers are combined into higher speed PCM buses to
simplify transport across the system backplane. The transceiver can be configured to allow PCM data to be
multiplexed into higher speed buses eliminating external hardware, saving board space and cost.
The 8.192MHz interleaved PCM bus option (IBO) allows four PCM data streams to share a common bus. See
Figure 11-1
for an example of four transceivers sharing a common 8.192MHz PCM bus. The receive elastic stores
of each transceiver must be enabled. Via the IBO register the user can configure each transceiver for a specific
bus position. For all IBO bus configurations each transceiver is assigned an exclusive position in the high-speed
PCM bus. The 8kHz frame sync can be generated from the system backplane or from the first device on the bus.
All other devices on the bus must have their frame syncs configured as inputs. Relative to this common frame
sync, the devices will await their turn to drive or sample the bus according to the settings of the DA0, DA1, and
DA2 bits of the TR.IBOC register.
11.1 Channel Interleave Mode
In channel interleave mode, data is output to the PCM data-out bus one channel at a time from each of the
connected devices until all channels of frame n from each device has been placed on the bus. This mode can be
used even when the transceivers are operating asynchronous to each other. The elastic stores will manage slip
conditions.
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