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TSUB7320 USB receiver equalization

user4360173
Prodigy 30 points
Other Parts Discussed in Thread: TUSB7320

Hello,

I am trying to understand the USB receiver phy equalization settings of the TUSB7320
PORT1_EQ_OV
PORT1_EQ_FUNC
PORT1_EQ_INIT
On our controller
- Equalizer Control Register E8h
- Custom PHY Transmit/Receive Control Register ECh
are both 0000 0000h.

Does it mean that no equalization is done or is it done?
According to the datasheet Port 1 Equalization Override (PORT1_EQ_OV) = 0 means that the default equalization settings are not overridden. But what are the default equalization settings? 

I was astonished that it is possible to switch of receiver  equalization.
I had thought the receiver equalization using the TSEQ sequence was part of the USB 3.0 standard. Is it really  possible to deactivate it on the TUSB7320?

Thanks,
Christian

  • 0
    TI__Guru* 76130 points
    Hello,
    You can see the default setting on Tables 8-1, 8-2 and 8-3 in the datasheet.
    For example, a value of 0x00 in the PORT_EQ means no adaptive equalization.
    Regards
  • 0 in reply to Elias Villegas M.
    Prodigy 30 points

    I already spent some time trying to interpret the datasheet.

    > PORT1_EQ_OV: "Port 1 Equalization Override. When this bit is set to ‘1’, the TUSB73X0 overrides the default equalization settings for port 1 with the values in the > PORT1_EQ_FUNC field and the PORT1_EQ_FUNC field of the Equalizer Control Register."

    To me this means PORT1_EQ_FUNC and PORT1_EQ_FUNC are only relevant if PORT1_EQ_OV==1.
    On the other hand, if PORT1_EQ_OV==0 the fields PORT1_EQ_FUNC and PORT1_EQ_FUNC are irrelevant. Now why should I care then about their value?

    Nowhere is written what the settings are if the enable bit (PORT1_EQ_OV) is not set.

    br Christian