ZL50057 ZARLINK [Zarlink Semiconductor Inc], ZL50057 Datasheet - Page 42

• Manufacturer Part Number: ZL50057
• Description: 12 K-Channel Digital Switch with High Jitter Tolerance, Per Stream Rate Conversion (2, 4, 8, 16, or 32 Mbps), and 48 Inputs and 48 Outputs
• Manufacturer: ZARLINK [Zarlink Semiconductor Inc]

4.4
The data (channel control bit) transmitted by BCSTo0-3 replicates the Backplane Output Enable (BE) bit of the
Backplane Connection Memory, with a LOW state indicating the channel to be set to high impedance. Refer to
“Backplane Connection Memory Bit Definition,” on page 61 for more details.
The BCSTo0-3 pins transmit serial data (channel control bits) at 16.384 Mbps, with each bit representing the
per-channel high impedance state for a specific stream. Eight output streams are allocated to each control line as
follows:
•
•
•
•
The channel control bit location, within a frame period, for each channel of the Backplane output streams is
presented in Table 5, BCSTo Allocation of Channel Control Bits to Output Streams (Non-32 Mbps Mode).
As an aid to the description, the channel control bit for a single channel on specific streams is presented, with
reference to Table 5:
1. The channel control bit corresponding to Stream 0, Channel 0, BSTo0_Ch0, is transmitted on BCSTo0 and is
2. The channel control bit corresponding to Stream 28, Channel 0, BSTo28_Ch0, is transmitted on BCSTo0 in
The BCSTo0-3 pins output data at a constant data rate of 16.384 Mbps, independent of the data rate selected for
the individual output streams, BSTo0-31. Streams at data rates lower than 16.384 Mbps will have the value of their
respective channel control bit repeated for the duration of the channel. The bit will be repeated twice for 8.192 Mbps
streams, four times for 4.096 Mbps streams and eight times for 2.048 Mbps streams. The channel control bit is not
repeated for 16.384 Mbps streams.
Examples are presented, with reference to Table 5:
3. With stream BSTo4 selected to operate at a data rate of 2.048 Mbps, the value of the channel control bit for
4. With stream BSTo8 operated at a data rate of 8.192 Mbps, the value of the channel control bit for Channel 1
BCSTo0 outputs the channel control bits for streams BSTo0, 4, 8, 12, 16, 20, 24, and 28.
BCSTo1 outputs the channel control bits for streams BSTo1, 5, 9, 13, 17, 21, 25, and 29.
BCSTo2 outputs the channel control bits for streams BSTo2, 6, 10, 14, 18, 22, 26 and 30.
BCSTo3 outputs the channel control bits for streams BSTo3, 7, 11, 15, 19, 23, 27 and 31.
advanced, relative to the frame boundary, by 10 periods of C16o.
advance of the frame boundary by three periods of output clock, C16o. Similarly, the channel control bits for
BSTo29_Ch0, BSTo30_Ch0 and BSTo31_Ch0 are advanced relative to the frame boundary by three periods of
C16o, on BCSTo1, BCSTo2 and BCSTo3, respectively.
Channel 0 will be transmitted during the C16o clock period nos. 2040, 2048, 8, 16, 24, 32, 40 and 48.
will be transmitted during the C16o clock period nos. 9 and 17.
BORS Asserted LOW, Non-32 Mbps Mode
Zarlink Semiconductor Inc.
ZL50057/8
42
Data Sheet