ZL50075GAC ZARLINK [Zarlink Semiconductor Inc], ZL50075GAC Datasheet - Page 15

• Manufacturer Part Number: ZL50075GAC
• Description: 32 K Channel Digital Switch with High Jitter Tolerance, Rate Conversion per Group of 2 Streams (8, 16, 32 or 64 Mbps), and 64 Inputs and 64 Outputs
• Manufacturer: ZARLINK [Zarlink Semiconductor Inc]

switch capacity is reduced to 512 channels when operating at 16 Mbps and to 256 channels when operating at
8 Mbps.
1.4
Table 1 shows the maximum number of streams available at different bit rates. The ZL50075 deactivates unused
streams when operating at the higher bit rates as shown in Table 2.
For 65 Mbps operation, only those inputs and outputs in the TDM ’A’ streams are active. For 32 Mbps, 16 Mbps and
8 Mbps operation, the inputs and outputs in the TDM ’A’ and ’B’ streams are active.
Note that if the internal system clock is not used as the clock source, there are limitations on the maximum data
rate. See Section 2.0 for more details.
1.4.1
See Section 14.4, Group Control Registers, for programming details. The data rates are set with the Input Stream
Bit Rate (bits 3 - 2) and the Output Stream Bit Rate (bits 19 - 18) in the Group Control Registers 0 - 31 (GCR0 - 31).
For the ZL50075, the bit rates of the inputs and outputs are programmed independently, in groups of 2 streams.
Depending on the rate programmed, the active streams in the group will be as indicated in Table 2.
For example:
•
•
1.5
The ZL50075 supports rate conversion from any input stream rate to any output stream rate.
An example of ZL50075 rate conversion is given in Figure 3. The output stream rates do not have to follow the input
stream rates. In this example, on the input side of the switch you can have 24 streams operating at 65.536 Mbps
(24,576 channels - 24 groups with 1 stream in each group), 8 streams operating at 32.768 Mbps (4096 channels - 4
groups with 2 streams in each group) and 8 streams operating at 16.384 Mbps (2048 channels - 4 groups with 2
streams in each group) with no streams operating at 8.192 Mbps. This results in an input capacity of 30,720 input
channels. This is less than the full capacity of the device as some groups are operating at less than 32 Mbps. As
the output streams do not have to follow the input streams, they can be configured so that 15 streams operate at
65.536 Mbps (15,360 channels - 15 groups with 1 stream in each group), 28 streams operate at 32.768 Mbps
(14,336 channels - 14 groups with 2 streams in each group), 2 streams operate at 16.384 Mbps (512 channels - 1
group with 2 streams in the group) and 4 streams operate at 8.192 Mbps (512 channels - 2 groups with 2 streams in
each group). This results in an output capacity of 30,720 output channels. This is less than the full capacity of the
device as some groups are operating at less than 32 Mbps.
if input stream group #1 is programmed for 65 Mbps: STiA1 is active; STiB1 is not active
if output stream group #15 is programmed for 32 Mbps, 16 Mbps or 8 Mbps: SToA15 and SToB15 are active
Input and Output Rate Selection
Rate Conversion
Per Group Rate Selection
Input or Output Group n
STiAn / SToAn
STiBn / SToBn
(n = 0 - 31)
Table 2 - TDM Stream Bit Rates
Not Active
65 Mbps
Active
Zarlink Semiconductor Inc.
ZL50075
15
32 Mbps
Active
Active
16 Mbps
Active
Active
8 Mbps
Active
Active
Data Sheet