Hi Team,
My customer has expressed that they are noticing some strange behavior with the DP83867E in which they state the bandwidth is not balanced between the TX and RX path of the device. The RX path appears to have much lower bandwidth when running at 1000baseT. Below are some answers to a few questions that I asked, but I'm hoping to get some additional tips on what to look into.
1. Which MAC interface you are using? RGMII?
root@lpb00000000:~# dmesg | grep mac
[ 1.360788] macb ff0e0000.ethernet: Not enabling partial store and forward
[ 1.361748] macb ff0e0000.ethernet eth0: Cadence GEM rev 0x50070106 at 0xff0e0000 irq 30 (00:0a:35:00:22:01)
[ 30.882833] macb ff0e0000.ethernet: gem-ptp-timer ptp clock registered.
[ 31.908001] macb ff0e0000.ethernet eth0: link up (1000/Full)
2. Are you implementing any internal delays in the PHY?
reg:0x86 val:0x006d
RGMII Transmit Clock Delay: 0110: 1.75 ns
RGMII Receive Clock Delay:1101: 3.50 ns
3. What are your strap configurations?
reg:0x6e val:0x00a8
reg:0x6f val:0x3000
4. What’s the value of register 0x000A?
reg:0x0a val:0x3800
5. What oscillator is being used?
P/N: ABM8-25.000MHZ-B2-T.
Thanks,
Mitchell
