Intel® IXP42X product line and IXC1100 control plane processors—High-Speed Serial
Interfaces
Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
456 Order Number: 252480-006US
4.096 MHz 2 T1/E1 512 2
8.192 MHz 4 T1/E1 1,024 2
Notes:

1. These clock speeds are supported using the HSS API. However, the GCI protocol is not

supported by the IXP400 software.

2. When the frequencies of 2.048, 4.096, or 8.192 MHz are used for T1, the data rate for each T1

remains at 1.544 MHz by making certain time slots within a frame unassigned and with no data.

The IXP425, IXP423 and IXP421 network processors’ HSS can be configured to discard

unassigned time slots.

Table 156. HSS Tx/Rx Clock Output Frequencies and PPM Error
HSS Tx/Rx
Frequency Min. Frequency
(MHz) Avg. Frequency
(MHz) Max. Frequency
(MHz) Avg. Frequency Error
(PPM) Notes
512 KHz 0.508855 0.512031 0.512769 -60.0096 1, 2, 3
1.536 MHz 1.515 1.536 1.55023 -60.0096 1, 2, 3
1.544 MHz 1.515 1.5439 1.55023 +60.0024 1, 2, 3
2.048 MHz 2.01998 2.0481 2.08313 -60 .0096 1, 2, 3
4.096 MHz 3.92118 4.0962 4.16625 -60 .0096 1, 2, 3
8.192 MHz 7.4066667 8.1925 8.3325 -60.0096 1, 2, 3
Notes:

1. These HSS Tx/Rx clock output frequencies are based on the set-up parameters in Table155.

2. Characterization data of the HSS Tx/Rx clock output frequency data was determined by silicon simulation.

3. The parts-per-million (PPM) error rate is calculated using the average output frequency versus the ideal frequency.

Table 157. HSS Tx/Rx Clock Output Frequencies And Their Associated Jitter Characterization
HSS Tx/Rx Clock
Output Frequency Pj Max. (ns) Cj Max. (ns) Aj Max. (ns)
512 KHz 12.189 15 18.283
1.536 MHz 9.063 15 86.102
1.544 MHz 12.359 15 210.099
2.048 MHz -8.204 15 118.957
4.096 MHz 10.9 15 190.742
8.192 MHz 12.951 15 226.634
Note: For jitter definitions, see Table 1 59.
Table 158. HSS Frame Output Characterization
HSS Tx/Rx Frequency Frame Size (Bits) Actual Frame Length (µS) Frame Length Error (PPM)
512 KHz 32 62.496249 -60.0096
1.536 MHz 96 62.496249 60.016
1.544 MHz 193 125.007499 60.0024
2.048 MHz 256 124.9925 -60.0096
Table 155. HSS Tx/Rx Clock Output