Trenz Electronic GmbH Support Forum

Trenz Electronic Products => Trenz Electronic FPGA Modules => Topic started by: maria on August 18, 2015, 06:00:26 PM

Title: Using I2C to access MEMS on TE0720
Post by: maria on August 18, 2015, 06:00:26 PM
Hi,

I would like to access MEMS on TE0720 board. But I'm confused because I'm using the TE0720-01 board version but I didn't find the corresponding documentation.
The documentation I found is for the TE0720-02 version and I'm not sure it is fully compatible.
So I have some questions :
- Are the following SC pins/FPGA pins connections the good one ?
   - SCL from FPGA : X1 to L16
   - SDA from FPGA : X7 to N22
   - SDA to FPGA : X5 to P22
   - MEMS interrupt : X3 to N15
- After reading the PCN TE0720-01 to TE0720-02 I understand there is a mux, controlled by X0 SC pin, on the I2C bus to select MEMS or RTC peripheral. How should I use X0 to access MEMS ?
- I'm using a TE0701 carrier board and the default config for VCCIO34 is set to 3.3V. Is it correct to use the I2C peripheral bus or should I change it to 2.5V ?

Thanks.
Best regards.
Title: Re: Using I2C to access MEMS on TE0720
Post by: Antti Lukats on August 19, 2015, 09:42:37 AM
X0 pin is not used or needed on TE0720-02, both RTC and MEMS would be on the same I2C bus.

But currently TE0720-02 all standard assembly variants are shipped with MEMS sensor not installed.

Title: Re: Using I2C to access MEMS on TE0720
Post by: maria on August 19, 2015, 10:24:11 AM
That's what I understood for TE0720-02. But what about TE0720-01 (which is the board I'm using)?
Title: Re: Using I2C to access MEMS on TE0720
Post by: Antti Lukats on August 19, 2015, 11:43:30 AM
SC CPLD has separate IO bank that is powered from the same VCCIO as the zynq bank it is connected to.

the I2C bus is on another bank of the SC, so changing IO standard on zynq banks does not change the I2C bus itself (RTC mems.)