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tknopp / RedPitayaDAQServer

Advanced DAQ Tools for the RedPitaya (STEMlab 125-14)
https://tknopp.github.io/RedPitayaDAQServer/dev/
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Single image for both master and slave #2

Closed jeanminet closed 4 years ago

jeanminet commented 6 years ago

Hello,

I was wondering if it was possible to use the same bitstream for both master and slave. Would this connection work ? :

screenshot from 2017-10-04 13-09-07

Best, Jean

tknopp commented 6 years ago

Hi Jean, it would be really great if this would be possible. I just know that Jonas tried something which did not work. He meant that the issue is, that the slave has no clock at that time when this decision was made. I cannot comment on the FPGA stuff since I only did the entire C stuff. Ping @jbeuke therefore.

jonschumacher commented 6 years ago

@jeanminet My first idea was to expose the master/slave settings to the cpu via a configuration register. This did not work, since I need a clock for the register which I don't get, if the clock selection is wrong. Your idea is actually a really nice one since the locked output of clk_wiz_1 should only be high if a clock is supplied via the daisy chain connector. I will add this to the blockdesign and have @tknopp test it in hardware ;)

tknopp commented 6 years ago

yes sure, I can test. You could make a branch that I can test.

jonschumacher commented 6 years ago

Apparently, this does not work as expected. The acquisition pointer sometimes stops or jumps, which makes the acquisition unreliable. Since using two different bitfiles for master and slave is not a major issue, I postpone digging further for a solution. Help is appreciated though!

mgraeser commented 4 years ago

I included the following solution to the branch v2: image The select is driven bei ext_DIO0_N. On the other side of the BlockDiagram ext_DIO1_N is given a constant 0. Now the DIO0_N is physically between a high (3.3V on External conn) and low (DIO1_N). With a jumper between DIO1_N and DIO_0_N the device is set as Master. Between 3.3V and DIO0_N it is set to slave. The advantage here is that the DIOs do not need the clock to work.