ASIX ELECTRONICS CORPORATION

17

CONFIDENTIAL

AX88872P Swipeater Controller

PRELIMINARY

1 : 1518 Byte

All of the above signals are pull-up for default values.

Note 1 :

The calculation formulae of Traffic Utilization between ASIX and NetCom is difference, so you will get

different results when using SmartBit (SB) testing this item.

We found the SmartBit calculate the Utilization without include 96 Bit time inter frame gap (IFG). So the utilization

value can be 100%. As well as we found SB used min packet size (64 byte) and min IFG (96 bit-time) as 100% utilization.

In theory, when max packet size (1518 byte) and min IFG the utilization will be more than 100%, but SB also treat it as

100%.

In our AX88872 design, we use real cable bandwidth as calculation base. We calculate the bit counts of carrier within a

unit time. Because of the existence of inter frame gap, In our calculation 100% utilization is impossible. So the above two

cases (64 byte packet size and 1518 byte packet size with min. IFG), we will count as 85.7% and 99.2%.

If using SB test result to indicate utilization LED the value must be modified. See the following reference table.

ASIX’s Utilization%

1

5

10

15

30

60

SmartBit’s Utilization%

2

7

12

17

34

68