TC397 Ethernet transmit speed

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huskie
Level 2
Level 2
5 replies posted First solution authored 10 sign-ins

Hello

Recently we have been using the TC397 to test the Ethernet transmission speed.

We use the LWIP stack, Transmission using TCP.

But the speed we tested was only about 200Mb/s, not 1000Mb/s.

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3 Replies
Di_W
Moderator
Moderator
Moderator
500 solutions authored 1000 replies posted 250 solutions authored
Hi huskie,
According to datasheet of RTL8211F(I)-CG
The 8-bit-wide data is recovered and is sent to the RGMII interface at a clock speed of 125MHz
Please check if 125MHz is used.
And the stack may limit the speed also.
dw
 
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huskie
Level 2
Level 2
5 replies posted First solution authored 10 sign-ins

Hi

 

RTL8211 link speed is 1000M

but RTL8211 CLKOUT pin is only 25Mhz.

image.png

 

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Di_W
Moderator
Moderator
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500 solutions authored 1000 replies posted 250 solutions authored

Hi huskie,

Please see this chapter:

 

7.11.1.RGMII 
Among the RGMII interface in 100Base-TX and 10Base-T modes, TXC and RXC sources are 25MHz and 2.5MHz respectively; while in 1000Base-T mode, TXC and RXC sources are 125MHz. TXC will always be generated by the MAC and RXC will always be generated by the PHY.

 

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