I'm working on a 5P1105ALL-EVB.
Timing commander cannot see any connection to the board. I think the FTDI drivers are ok, because 2 COM ports appear upon plugging in the board, but TC says it can't find any device when using either address 0xD4 (from the datasheet), or 0x6A (the equivalent 7 bit address).
I connected a Raspberry Pi to it via I2C and the AARDVARK connector, and it can see and manipulate the registers of the 5P1105, so the inability of Timing Commander to connect is an inconvenience rather than a fatal problem.
On to my immediate question: should changes to registers that define the clock outputs have an immediate affect? Or are the outputs set only on power up?
The default configuration on the board generates a CMOS signal and its inverse on CLK1, HCSL3 on CLK2, LVDS on CLK3 and LVPECL on CLK4.
I set 0x62, 0x64 and 0x66 to 0xBB to generate a CMOSD output in CLK2, CLK3 and CLK4, but I saw no change in the outputs. I tried toggling the SD/OE pin, but that didn't help. Do I have to shut it down, as detailed in the "Entering Shutdown Mode through I2C" section of the Register Descriptions and Programming Guide?
By the way, I have doubts about the accuracy of those instructions for entering shutdown mode because it appears the instructions in steps 1 and 2 are mixed up. Step 1 says to write 001ss000 to tristate the outputs, but that just sets it to single-ended CMOS. Step 2 says to set the outputs to single-ended CMOS by writing 0x00 to register 0x68, but it appears that would tristate the outputs. Step 4 then says to set a special value in an undocumented registers to disable otherwise-unmentioned dividers. It does not instill confidence.
From Our Engineering Team:
Here are my comments and my recommendations in green.
[CM] It’s weird, please could you check the R65/R66/R27/R28 resistors are correctly mounted and with good indicated values in the evb user guide.
[CM] Check the I2C signals when the FTDI drives lines, the two signals should be toggling.
[CM] Could you confirm the OUT0_SETB_I2C pin is set to 0 during the power up.
I assume it’s the case, otherwise the parts won’t connect with AARDVARK.
[CM] Could you read the 0x00 register with the aardvark probe. The bit[0] should be 1, if I2C address is 0xD4.
[CM] It depends of register, for certain registers, you couldn’t notice any immediate changes.
I suggest toggling the following Shutdown/OE registers, you should observe changes on the outputs.
[CM] Normally, that should change. I wonder if the I2C access are valid.
[CM] Here is the attached programming guide, see the Figure 2. Shutdown Logic.
REN_5P11xx-RegDesc-Program-Guide_GDE_20170811.pdf
I'm not using the Aardvark probe, I'm just using the connector as a convenient means of access to the I2C bus. Although I can't reach the 5P1105 via TC, I do have solid I2C access via a Raspberry Pi.
I'm measuring R27 at 2.7K and R28 at 1K, and R65 and R66 at 0. The Raspbery Pi is able to work even with these values, but maybe the FTDI chip can't.
Here is a specific situation I can't get to work. The default value for CLK2 is to have a register value of 0x5b, which means an output type of HCSL33. I would like to have the output type be CMOSD, the same as the default output type for CLK1. I write 0xbb to register 0x62, and I read it back to verify it was written. However, the output type of CLK2 doesn't change.
I try a global shutdown. I write 0x81 to register 0x10 to make the SD/OE input means shutdown and not output enable. Using the DIP switch on the board, I change the OE value from ground to +3.3, and I verify that the outputs are off, then switch SD/OE back to ground again.
Register 0x62 still reads 0xbb, but the output type hasn't changed. How can I change this output type?
[CM] Are the JP19/18/20/21 jumpers mounted?
Here is a specific situation I can't get to work. The default value for CLK2 is to have a register value of 0x5b, which means an output type of HCSL33.
[CM] You need to implement an HCSL termination, for turning on the driver.
Please, Mount the R35=R36=50ohm resistors. You should see HCSL clock on OUT2.
[CM] Could you try the same operation with another output.