I2C basic - trying to analyse the signals without slaves

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Anonymous
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Hi,

   

I am using the 4200 BLE pioneer kit board to interface an external FRAM chip (not the one on the board itself). Since it works little bit different I will understand the I2C protocol and try to analyse the signals with a logic analyser.

As a base project I use the simple fram test project from this topic http://www.cypress.com/forum/psoc-4-ble/fram-ble-pioneer-board-and-i2c.
This project works as expected with the onboard Fram chip (pins 5.0 SDA and 5.1 SCL), so I know the I2C component is properly working as such.  The program tries to write to and read from FRam every second.
Now I map other I2C capable pins to drive an external I2C bus. There are no slaves on the bus and each line is pulled up by a 2K resistor to ca. 3.3 V  (voltage divided from 5 V). Each line has a logic analyser probe attached and I do not see any activity on the lines. SCL is always low and SDL always high.
Shouldn't there be at least START sequences from the master?
When I attach a slave though, I can see full communication. Is this the expected behaviour?

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