No I2C ACK from CS43L22

Feb 20, 2012 3 Replies
U

Hello,



I am trying to bring up the devices on the STM32F4 Discoveryboard. The CS43L22 is still giving headaches. I query the I2C Bus by sending out address



2,4, ... 0xfe and if I get an ACK I declare the device available. I have done this on several boards before. With the CS43L22 on the STM32F4 Discoveryboard even so I can verify the waveforms with an Logic Analyser and all unrelated pins are set to safe level, there is no reaction from the device.

Is there anything special I have to observe with the CS43L22?



Thanks


Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt --------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------
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L

looked at this: stm32f4_discovery_audio_codec.c from

formatting link
?

-Lasse

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U

I looked there to but could not decipher anything special...

Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt --------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------
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T

The I2C addressing is a bit confusing, as the device addresses are doubled before sending out to the bus. The LS bit contains the read/write request. The addresses for the chip may be 0x4a or 0x4b, which are 0x94 to 0x97 (with r/w-) on the bus.

The maximum speed of the chip is specified at 100 kHz. Have you checked that it is not exceeded? Does the chip respond with an ACK?

For testing, the chip ID register may be a good candidate.

Tauno Voipio
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