Current Server Time: 05:20 (Central Europe)

#apertus IRC Channel Logs

2020/04/07

Timezone: UTC


02:15
Spirit532
left the channel
02:18
Spirit532
joined the channel
02:20
Bertl_oO
vup: yes, what's the plan there?
03:05
Spirit532
left the channel
03:09
Spirit532
joined the channel
04:00
comradekingu
left the channel
04:01
comradekingu
joined the channel
04:09
Bertl_oO
off to bed now ... have a good one everyone!
04:09
Bertl_oO
changed nick to: Bertl_zZ
04:23
Spirit532
left the channel
04:27
Spirit532
joined the channel
05:25
BAndiT1983|away
changed nick to: BAndiT1983
06:04
megora_
left the channel
07:02
namibj
left the channel
07:41
Dest123
joined the channel
07:42
Dest123
left the channel
07:43
Dest123
joined the channel
08:03
WalterZimmermann
left the channel
08:03
WalterZimmerman4
joined the channel
08:12
omar31
joined the channel
10:06
Bertl_zZ
changed nick to: Bertl
10:06
Bertl
morning folks!
10:50
Dest123
left the channel
11:22
vup
Bertl: well we want to test up to which frequencies we can reliably use a connector
11:31
Bertl
thought so, but what's the plan here?
11:32
Bertl
some kind of loopback module?
11:32
Bertl
or a test board which uses the connector in question or something completely different?
12:46
vup
Bertl: well we are starting with the 100mil headers that are already present on the current micro, using a wire bridge to loopback one pin to another
12:54
Bertl
wire bridge?
12:54
Bertl
you mean a cable?
12:59
vup
yeah
12:59
Bertl
it will be tricky to match the 50/100Ohm there
13:00
vup
well the connector itself also doesn't match 50/100Ohm, so keeping the cable short shouldn't make it much worse i would think
13:00
Bertl
really depends on the impedance changes
13:01
vup
yeah, this isn't really meant as a decisive test for it not working
13:02
vup
but if it works with that setup, it should definitely work with a more proper setup
13:02
Bertl
hard to tell, could work by accident as well
13:02
vup
how so?
13:02
Bertl
what exactly is the goal of the test?
13:03
vup
well mainly figuring out if we can just use 100mil headers for the sensor connection
13:04
Bertl
okay, so the connection goes 'main PCB' - 100mil header - 'sensor PCB'
13:04
vup
yes
13:04
Bertl
and the data transfer is typically in the other direction, yes?
13:04
vup
for most sensor I would imagine so
13:05
vup
the cmv12k has a high speed clock input, right?
13:05
Bertl
okay, so the best setup would be to create a dummy senor PCB which consists of a properly routed 'loop' from I/Os of one side of the connector to the other
13:05
Bertl
e.g. if you have 8 LVDS pairs for sensor connection
13:06
Bertl
create loops between the outer most down to the innermost
13:06
Bertl
all properly routed on the dummy sensor board
13:07
Bertl
this way you know when the loopback test works at a given frequency, the sensor will be fine and in safe range
13:07
Bertl
(because you traverse the connector twice for every loop)
13:07
vup
yes that sounds like a good setup
13:08
vup
the hope was we can forgo the need of the dummy sensor board if it works with the current setup
13:08
Bertl
well, you can test that as well, but I wouldn't draw too many conclusions from that
13:10
Bertl
capacitance and inductance might just cancel each outher out at the freqeuncy you test with
13:10
vup
hmm yeah maybe
13:11
vup
I was planning on doing a frequency sweep anyways (roughly 250MHz DDR -> 500MHz DDR)
13:11
Bertl
okay, that will definitely get better results
13:13
vup
using that I think we should be able to rule out most accidents
13:13
Bertl
could work
13:13
vup
but i guess we will just have to see how the results look like and then decide if we want to test it with a dummy sensor board or not
13:13
Bertl
definitely let me know how it goes :)
13:13
vup
yes, will do
13:33
BAndiT1983
changed nick to: BAndiT1983|away
15:00
Bertl
off for now ... bbl
15:00
Bertl
changed nick to: Bertl_oO
15:06
WalterZimmerman4
left the channel
15:22
kunalghosh[m]
left the channel
16:20
megora
joined the channel
17:29
BAndiT1983|away
changed nick to: BAndiT1983
17:55
Bertl_oO
changed nick to: Bertl
20:34
futarisIRCcloud
joined the channel
21:01
omar31
left the channel
21:08
BAndiT1983
changed nick to: BAndiT1983|away
21:51
megora
left the channel
22:43
futarisIRCcloud
left the channel