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From 07/17/2017 to 08/15/2017

08/15/2017

SB 01:57 AM PCB Development: EMI testing
Has the MitySOM-5CSX ever been involved in EMI testing? I'm getting reports from a customer that there is quite a bit of radiated noise at the DDR3 frequency range. They haven't given the details yet, but it would be great to know if y... Stephen Brown

08/03/2017

NH 07:25 PM Software Development: RE: Using EEPROM available on MitySOM-5CSX
We are using kernel version 4.1.22
-Nick
Nicholas Herbert
MW 07:22 PM Software Development: RE: Using EEPROM available on MitySOM-5CSX
What version of the kernel are you using? From our site? Version 3.16?
-Mike
Michael Williamson
NH 06:58 PM Software Development: RE: Using EEPROM available on MitySOM-5CSX
Mike,
I recently picked up this task and haven't been able to see the NOR flash device in the MTD devices list. On boot-up I get the following message:
[ 1.159717] cadence-qspi ff705000.spi: couldn't determine tshsl-ns
[ 1.1...
Nicholas Herbert

07/20/2017

MW 06:09 PM Software Development: RE: I2C Slave Communication Hanging
So I didn't respond right away as you are using verilog and I am more of a VHDL guy, but there is an open drain primitive called OPNDRN.
You can see an example of it inferred in VHDL here (bottom of file) for I2C routing like you are ...
Michael Williamson
JP 05:43 PM Software Development: RE: I2C Slave Communication Hanging
We appear to have finally discovered the root cause of our issue. We actually had a self-inflicted bug where the SCL line on this one port was defined as "output" rather than "inout". Thus, we didn't really have the "open drain" we thoug... Jay Petrie

07/19/2017

JK 07:39 PM Software Development: RE: I2C Slave Communication Hanging
Dan,
I've attached 2 scope shots between the Aardvark as master and the ST1633 as slave:
1. A single byte write with a value of 0x01
2. A subsequent single byte read, which we expect to return 0x04 (and does, in this trace)
This ...
Jared Kirschner
JK 03:42 PM Software Development: RE: I2C Slave Communication Hanging
Dan,
We'll be conducting investigations this afternoon with both the Linux I2C kernel driver and a bit-bang I2C user-space module we just finished writing. As a part of those investigations, we'll send along a read request capture bet...
Jared Kirschner
DV 03:45 AM Software Development: RE: I2C Slave Communication Hanging
Jared,
To me it looks like the scope capture you've shown should be correct and as you've said there shouldn't be a stop condition between the first and second byte, which is why the clock stays low. Though the second byte isn't ack'e...
Daniel Vincelette

07/18/2017

JK 07:56 PM Software Development: RE: I2C Slave Communication Hanging
Some additional context / correction:
I2C2 and I2C3 are both configured the same way. If you replace "3" with "2" in the above example, and replace "DVI" with "TFT" (related to our ST1633 touch controller), the result is the I2C2 setu...
Jared Kirschner
CS 07:33 PM Software Development: RE: I2C Slave Communication Hanging
All,
This is the open drain primitive we are using for the I2C interfaces:
wire w_i2c3_scl_oe, w_i2c3_scl, w_i2c3_sda_oe, w_i2c3_sda;
assign DVI_SCL = (w_i2c3_scl_oe) ? 1'b0 : 1'bz;
assign DVI_SDA = (w_i2c3_sda_oe) ? 1'b0 : 1'b...
Clyde Shappee
MW 05:09 PM Software Development: RE: I2C Slave Communication Hanging
Are you using the open drain primitive in the top level of the FPGA project?
-Mike
Michael Williamson
JK 05:00 PM Software Development: RE: I2C Slave Communication Hanging
I've attached the driver source/header. I'm waiting to hear from the touch controller vendor whether I can share the protocol description. Jared Kirschner
JK 04:50 PM Software Development: RE: I2C Slave Communication Hanging
We are using I2C2 routed through the FPGA fabric (see image "I2C2_Connector.PNG"). It does have pullups to the best of my knowledge (see image "I2C2_Pullups.PNG").
Though we initially tried to communicate via user space, the vendor in...
Jared Kirschner
MW 04:32 PM Software Development: RE: I2C Slave Communication Hanging
Also, Can you share a snippet of the user space code you are using to issue the read request?
Thanks.
-Mike
Michael Williamson
MW 04:15 PM Software Development: RE: I2C Slave Communication Hanging
Which I2C bus are you using? An HPS peripheral connected directly to HPS pins or routed via FPGA fabric?
This almost looks like there is no pull-up on the bus...
-Mike
Michael Williamson
JK 02:52 PM Software Development: I2C Slave Communication Hanging
We're experiencing a problem with I2C communications with a slave on address 0x55 on a MitySOM-5CSX, shown in the attached image (scope_3.png).
In the image, *a read is attempted, with the first byte NACK'd by the slave, and an invali...
Jared Kirschner
 

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