How to enable EMAC1 in RMII Mode to communicate with USB-ether device.

hb chen

Expert 2640 points

Dear Experts,

My TI RDK version: DVRRDK3.0. / Custom Board

There are two EMACs in DM8148. I use EMAC0 as RGMII mode to be a Ethernet port, it is working.

I want to connect DM8148 EMAC1 to a USB-Ether in RMII mode.

After setting corresponding register, I can’t ping USB Host, vice versa.

Could anyone help me check whether the register setting is correct ??!!

or anything that I missed ??!!

Attached file is the architecture of my board.

( https://dl.dropbox.com/u/27415803/Question1.doc )

3858.Question1.doc

1) Pinmux of EMAC1

RMII_REFCLK 0x48140B9C: 00040001

GMII0_TXD2 0x48140BEC: 00000002

GMII0_TXD3 0x48140BF0: 00000002

GMII0_TXD5 0x48140BF8: 00000002

GMII0_TXD6 0x48140BFC: 00000002

GMII0_TXD7 0x48140C00: 00000002

GMII0_TXEN 0x48140C04: 00000002

2) Control Module Register GMII_SEL Register (offset = 650h)

GMII_SEL Register 0x48140650: 00000306

3) PRCM Register RMII_REFCLK_SRC Register (offset = 2E8h)

RMII_REFCLK_SRC 0x481802E8: 00000000

>> I can’t adjust this register in board-ti8148evm.c by using omap_writel(0x00000001, 0x481802e8);

4) Kernel : select TICSPW Switch as Dual EMAC

thx

over 12 years ago

0 Viet Dinh over 12 years ago

TI__Genius 15310 points

Hi HB,

These are what I got from our EMAC expert:

1) This looks ok but it looks like “GMII0_TXD4 0x48140BF4: 00000002” is missing.

2) We think GMII_SEL would need to be set to 00000106 in this case.

3) Some of the Control Module register are usually protected. You need to make the MMR are unlocked before being able to write to these registers. See TRM section 3.3.3 MMR_Lock Register.

BR,

Viet

0 hb chen over 12 years ago in reply to Viet Dinh

Expert 2640 points

Dear Viet,

1) In schematic, GMII0_TXD4 0x48140BF4 is unsed. Thus I didn't pinmux this register.

2) 00000106 >> You mean I should configure EMAC1 to GMII / MII mode mode ??

3) I checked the code, the RMII_REFCLK_SRC Register (offset = 2E8h) base adderss should be 0x481C5000.

But when I use omap_writel(0x5, 0x481C52E8) in board init, kernel will be hang up ...I swill don't knwo why ....

0 Vladimir-XID over 12 years ago in reply to hb chen

TI__Genius 11470 points

HB,

About 1) You can check "Table 4-13 PINCNTLx Registers MUXMODE Functions" in the device datasheet around page 167 for 0x48140BF4

About 2) I think 0x106 represents this configuration:

GMII0_SEL: RGMII

GMII1_SEL: RMII

RGMII0_EN: RGMII mode

RGMII1_EN GMII / MII mode

which could be a proper configuration for your case.

About 3) Have you checked the MMR lock? As I mentioned in the other your forum thread, see the instructions in the wiki:

http://processors.wiki.ti.com/index.php/TI81xx_PSP_Porting_Guide

http://processors.wiki.ti.com/index.php/TI81xx_PSP_Porting_Guide#CPSW_RMII_Phy

Is everything described there followed?

Thank you.

Vladimir

0 hb chen over 12 years ago in reply to Vladimir-XID

Expert 2640 points

Dear Vladimir,

thx ~ RMII can work now ~

according to http://processors.wiki.ti.com/index.php/TI81xx_PSP_Porting_Guide#CPSW_RMII_Phy

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How to enable EMAC1 in RMII Mode to communicate with USB-ether device.