Using RMII1 and JTAG
Added by Jeong-Heon Shin about 9 years ago
I have two questions.
I have bought three modules with DevKit on Digikey.
But the Silicon revision is 1.0.
It's over a year in changing silicon, but you're selling old version up to now.
It's NOT GOOD.
First, MitySOM has I2C1_SDA on pin 147 and it's duplicated with RMII1_CRS_DV.
Does it cause a problem when I use RMII1_CRS_DV instead of I2C1_SDA?
Second, I have XDS510USB Pro emulator.
Is it works well without problem?
When I connect emulator to 14-pin JTAG header, it doesn't work with M3 core but work with A8 core only.
Is it correct or not?
My DevKit version is 4A, there's no explanation in Wiki.
RE: Using RMII1 and JTAG - Added by Alexander Block about 9 years ago
This specific issue is/has been dealt with through e-mail contact directly. However for others who may have similar questions I will provide answers here as well.
You are correct that Revision 1 Silicon modules are still in distribution at this point. For the large majority of customers there is no issue with Rev 1 silicon unless a faster CPU speed is needed (800MHz in Rev 2) or RMII2 access which was made available with Rev 2 AM335x Silicon. Arrangements are being made to allow for an exchange to Rev 2 modules in this instance.
It is not advised to use the I2C1_SDA pin in the RMII1_CRS_DV mode as that pin is connected to the modules EEPROM and there could be the possibility of corruption. This wiki page (https://support.criticallink.com/redmine/projects/armc8-platforms/wiki/Ethernet_Phy_Selection) discusses the available Ethernet MAC interfaces.
Concerning the Emulator and the M3 core we are not directly familiar with trying to debug that core. We tried to find some guidance from TI about the M3 and the only details really cover using the power management features and ensuring that the firmware for the core is in the proper place when a kernel is built. Here are the pages that contained some of this data but nothing about actually debugging the core: