ESP32 ethernet, SPI, JTAG pin questions

[Ankit Nikumbh]

Hello,

I am working on ESP-32 Wroom module. I want to know about how can I interface RMII signals to the MCU as I need Ethernet connection!!!!!!!

As there are different pins for MDC_out(any GPIO given in datasheet), MDI_in, MDO_out......

And for REF_CLK, can I connect it with EMAC_Tx_CLK ? Both are same or different??

Also for SPI interface I saw few discussion based on SPI signals(MTDI, MTCK, MTMS, MTDO). Please try to solve my confusion related to MISO, MOSI, SCK, CS... Which signal is related to MTDI/MTCK/MTMS/MTDO??

Try to reply ASAP

Thank you

[ESP_Sprite]

Please see http://www.espressif.com/sites/default/ ... t_en_0.pdf for documentation on which pins connect to the Ethernet MAC.

MTDI/MTDO/... are JTAG signals and don't have anything to do with SPI. You can look up the pins for SPI in the above document as well. If you don't mind a latency of 2 80MHz clock cycles and a slower SPI slave mode speed, you can also route the SPI pins to any other GPIO as well.

[Ankit Nikumbh]

Hi,

As I'm using Wroom-32 and I want to use RMII Interface then which pin provides 50MHz of clock output as a reference clock for PHY transceiver??? Either GPIO16(EMAC_CLOCK_OUT) or GPIO17(EMAC_CLOCK_OUT_180).....

And also, what will be the output of CLOCK_OUT1(IO0), CLOCK_OUT2(IO3) and CLOCK_OUT3(IO1)???

[rudi ;-)]

Hi,

As I'm using Wroom-32 and I want to use RMII Interface then which pin provides 50MHz of clock output as a reference clock for PHY transceiver??? Either GPIO16(EMAC_CLOCK_OUT) or GPIO17(EMAC_CLOCK_OUT_180).....

And also, what will be the output of CLOCK_OUT1(IO0), CLOCK_OUT2(IO3) and CLOCK_OUT3(IO1)???

push!
1++


why this not work for use RMII CLK Out ?

Code: Select all

PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO16_U, FUNC_GPIO16_EMAC_CLK_OUT);

what is missing, what is need, what we have to read?
see no CLK set. is this the standard 50MHz CLK or how we can set/use FUNC_GPIO16_EMAC_CLK_OUT
can we use this in silicon V1 ?


best wishes
rudi

[RobinC]

push
1++

Does anyone in Espressif have any details on actually getting the emac to work with rmii (specifically with 50MHz clock out to clock the rmii)?

[rudi ;-)]

push
+1

https://github.com/espressif/esp-idf/issues/372

we play now more as 5 days only in this, now its time to say from espressif team:

- Yes it run..
- you must use this hardware...
- you must use this hardware reference ..
- here is the link


or


- no, just in time not supportet, its an theoretical example



I can not believe that this example was even tried at espressif and it works.
Recently a pin was added which switched the PHY Power.
https://github.com/espressif/esp-idf/co ... 134355011e

the ip get function is based on wifi station and ap ip function
https://esp32.com/viewtopic.php?f=2&t=1249&p=5518#p5518

btw the question is unanswered - not sure is this the reason for not get an ip

I hate this quiet question
We all sit at the pc and wait for reply!
And if it's just a "we're testing that ..."

[RobinC]

Followup: got both tlk110 and lan8720 working. Key for me was physically routing CRS/DV to GPIO27. I'm using the onboard crystal/oscillator on the phy eval boards and haven't tried generating a clock from the ESP32.

Robin

[colman]

Since GPIO0 is the strapping pin for booting mode, how do you handle it if it is used for RMII clock input? How do you disconnect it during reset?

Colman

[rudi ;-)]

Since GPIO0 is the strapping pin for booting mode, how do you handle it if it is used for RMII clock input? How do you disconnect it during reset?

Colman

clk disable

[colman]

I am using LAN8720, it always output the 50MHz RMII clock even though it is being reset, there is no clock enable/disable option via software programming.

Colman