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Part Number: AM623 Other Parts Discussed in Thread: SK-AM62
Hello,
Let me confirm about below.
* I would like you to confirm how user can assert TX_EN for RMII interface. I'm checking description on TRM, it seems that there is no information about this. Could you please confirm ?
I would like you to confirm about detail of following description.
>I would expect the TX_EN for RMII interface to be enabled as part of the data interface protocol. Do you mean when user send packet to TX buffer, TX_EN is automatically genearted ?
I extracted the description from an app note referenced below..
3.5 TX_EN - Transmit Enable TX_EN indicates that the MAC is presenting di-bits on TXD[1:0] for transmission. TX_EN shall be asserted synchronously with the first nibble of the preamble and shall remain asserted while all di-bits to be transmitted are presented. The MAC should assert TX_EN negated prior to the first REF_CLK rising edge following the final di-bit of a frame. TX_EN shall transition synchronously with respect to REF_CLK. https://www.ti.com/lit/an/snla076a/snla076a.pdf
Please review the RMII specifications for additional information.
I'm sorry I can not access above URL. It seems that this is TI internal site, can you extract the point ?
- 2 - >Could you please help me understand the context of the query for me to support better. Now, we have problem on case of RMII. Customer create custom board with RMII PHY and connect AM623. The SDK condition is Linux SDK(ver 08_05_00_21).
The problem of above is user can not observe TX_EN when they send packet from AM62.(Wh have already confirmed "link up".) If you would like to know detail and need detail discussion, please let me communicate internally.
However, above is the reason why we want to know how user can output TX_EN.
I added the below input i received from Ryuuichi, machida,
Can you please check with customer on the RMII driver they are using. Was this modified by customer? How was the driver verified? I heard that customer use kernel standard RMII driver which are included in Linux SDK (Ver 08_06_00_45).
The issue description is as below. Can you review and confirm if this is the same project and also clarify the issue observed to continue further analysis.
We have designed Ethernet RMII communication circuit on our new PCB using TI MCU and PHY. When Ethernet cable connects from this PCB to PC for the test, link up can be done (100Mbps, Full-duplex) but ping cannot success.
Parts name of MCU and PHY are the followings. MCU: AM6231ASGGGAALW PHY: DP83825IRMQR x2 (eth0, eth1) used as RMII master mode
We have designed the firmware of Ethernet communication module based on the one for SK-AM62. (Changed only some parameters and defines from for RGMII mode to for RMII mode.)
We have confirmed that the port mode setect of both eth0/eth1 is RMII. CTRL_ENET1_CTRL Register (Offset = 4044h) ENET1_CTRL_PORT_MODE_SEL: b001 - RMII CTRL_ENET2_CTRL Register (Offset = 4048h) ENET2_CTRL_PORT_MODE_SEL: b001 - RMII CTRL_ENET1_CTRL_PROXY Register (Offset = 6044h) ENET1_CTRL_PORT_MODE_SEL_PROXY: b001 - RMII CTRL_ENET2_CTRL_PROXY Register (Offset = 6048h) ENET2_CTRL_PORT_MODE_SEL_PROXY: b001 - RMII
Details of ping NG; PC --> PCB: PC send ARP request to PCB(as global packet), but PCB send no response message to PC. PCB --> PC: PCB send ARP request to PC(as global packet), then PC send the response message to PCB, but then PCB send ARP request to PC(as global packet) again. It repeats until ping command of PCB is stopped.
We measured the waveform of main signal lines around PHY. The waveforms of MDIO, MDC, 50MHzOut, TD_P/M, RD_P/M has the correct changes and seem no problem. But the waveforms of TX_EN, TX_D0, TX_D1, RX_D0, RX_D1, RX_ER, CRS_DV are always 0V with no change.
Please give us some advice if it can be guessed something suspicious by the above information, or if there are what we need to check more.
=> Please see attached file(txt file) about result. (Status of "From Line 1 to Line 210" is "Disabled link up" with PC, Status of "From Line 211 to Line 424" is "Enabled link up" with PC.)
