Is it possible, using data pins exept address pins?

[Jeff Kang]

Hi! this is KMDATA in KOREA.

I’ll assign 2 RGMII to 2 PHY each.
So there is no address bus available(Because RGMII2 take the address pins).
But the chip, I want to use is DM9000(ethernet controller), this chip has command based data bus interface, no address pins required.

And this is my question, is it a possible schem?
Does address pins can be used as RGMII, even though at external memory access cycles?
Because of my lack of English, I’ll attach block diagram.

Thankyou!
Kang

Attachments:

1. 

   address-data-bus.jpg
   

[Neeraj Dantu]

Jeff,

Please see the following inputs for your design:

1. It looks like TI does not support the PHY you are using: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/973865/am3358-network-port-expansion-with-dm9000?tisearch=e2e-sitesearch&keymatch=dm9000#. Note that GPMC interface is being used for interfacing between AM335x and DM9000. GPMC_AD[0:7], GPMC_CSN[1:2] are not available externally for OSD335x CSiP as they are used to connect to an eMMC inside the device.

2. Please see https://www.ti.com/tool/TMDSSK3358#design-files for an example of 2 RGMII ports being used for AM335x. All pins needed for RGMII1 and RDMII2 are present in OSD335x C-SiP. Please see pin mapping between AM335x and OSD335x CSiP here: https://octavosystems.com/app_notes/am335x-signal-to-osd335x-pins/

We recommend using a different PHY.

Best,
Neeraj

[Author]

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