AM5726: Gigabit Ethernet issue with RTOS

Hi Support,

my customer is playing with the Ethernet stuff on a custom board. They are using DP83867 PHY IC connected to the RGMII1 (Port 2 of the AM5726 GMAC_SW block). They compiled the ‘NIMU Basic Example’ with their board configurations (pinmux, etc.). MDIO seems working (they can read and modify PHY’s registers), they can also ping the network interface in 100Mbit full-duplex mode. If they connect the interface to a 1Gbit peer, they can see the “Negotiated connection: FullDuplex 1000 Mbs” message but cannot ping the interface anymore from the peer computer.

They can see by an oscilloscope activity in RGMII RX direction (125 Mhz signal on RXC_CLK signal, some moving data bits on RXD[3:0] wires) but no signal in TX direction, all TX RGMII wires are low.

This is the contents of the PHY’s registers when a 1Gbit peer is connected, ‘FullDuplex 1000 Mbs’ mode is negotiated, and the computer is continuously sending ping ICMP requests:

### PHY 1 registers:

###     [000] BMCR              0x1100

###     [001] BMSR              0x796d

###     [004] ANAR              0x01e1

###     [005] ANLPAR            0xcde1

###     [006] ANER              0x006d

###     [007] ANNPTR            0x2001

###     [008] ANNPRR            0x5006

###     [009] CFG1              0x0200

###     [00A] STS1              0x7800

###     [00D] REGCR             0x0000

###     [00E] ADDAR             0x0000

###     [00F] 1KSCR             0x3000

###     [010] PHYCR             0xf040

###     [011] PHYSTS            0xac02

###     [012] MICR              0x00d3

###     [013] ISR               0x0000

###     [014] CFG2              0x29c7

###     [015] RECR              0x0000

###     [016] BISCR             0x0000

###     [017] STS2              0x0040

###     [018] LEDCR1            0x6150

###     [019] LEDCR2            0x4444

###     [01A] LEDCR3            0x0002

###     [01E] CFG3              0x0002

###     [01F] CTRL              0x0000

###     [025] TMCH_CTRL         0xcde1

###     [02D] FLD_CFG           0x0000

###     [031] CFG4              0xac02

###     [032] RGMIICTL          0x00d3

###     [033] RGMIICTL2         0x0000

###     [037] SGMII_ANEG_STS    0x0040

###     [043] 100CR             0xa231

###     [055] SKEW_FIFO         0x0000

###     [06E] STRAP_STS1        0x0000

###     [06F] STRAP_STS2        0x3000

###     [071] BICSR1            0xac02

###     [072] BICSR2            0x00d3

###     [086] RGMIIDCTL         0x006d

###     [0D3] SGMIICTL1         0x0000

###     [0E9] SYNC_FIFO_CTRL    0x0200

###     [0FE] LOOPCR            0x0002

###     [134] RXFCFG            0x29c7

###     [135] RXFSTS            0x0000

###     [170] IO_MUX_CFG        0xf040

###     [172] GPIO_MUX_CTRL     0x00d3

###     [180] TDR_GEN_CFG1      0x1100

###     [1A7] ALCD_CTRL         0x2001

 Can you help me solving the issue?

Thanks and regards,

Alberto