Mar 02, 2021
09:22 PM
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Mar 02, 2021
09:22 PM
Hi,
I am seeing a problem with /CS activating and clock not rising fast enough for the desired SPI mode. External logic analyzer (Saleae) says this is not according to norm:
Clock should be high, when /CS is going "active".
I tried the settings for
BACON LPRE and LEAD but the only result is, that to clock starts cycling later:
I know the signals are looking bad, but that´s nothing i can change without any change in hardware. We already have the padmode on "maximum speed".
What i would need:
Is there any setting i may have missed, to set the clock to high before /CS is actived.
I am seeing a problem with /CS activating and clock not rising fast enough for the desired SPI mode. External logic analyzer (Saleae) says this is not according to norm:
Clock should be high, when /CS is going "active".
I tried the settings for
BACON LPRE and LEAD but the only result is, that to clock starts cycling later:
I know the signals are looking bad, but that´s nothing i can change without any change in hardware. We already have the padmode on "maximum speed".
What i would need:
Is there any setting i may have missed, to set the clock to high before /CS is actived.
- Tags:
- IFX
3 Replies
Mar 03, 2021
02:40 AM
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Mar 03, 2021
02:40 AM
Set the corresponding pins to speed grade 1 via register Pxx.PDRy, then you get the strong edges. The default value for the pins is speed grade 4/weak edge.
Mar 03, 2021
04:14 AM
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Mar 03, 2021
04:14 AM
As i said, we already set the pad speed to maximum speed.
Mar 03, 2021
08:10 AM
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Mar 03, 2021
08:10 AM
It seems you expect that the idle level is high for SCLK. Set the CPOL bit in the used ECON register. As I known is the SPI normally edge driven (changing edge and sampling edge) and not level driven.