05-24-2011 04:13 PM
Dear Sir:
I had question regarding to the I2C write.
Q1: Can we do burst write ( write 14 bytes data ) to the slave( our IC is slave)? and Mater is MY8451.
Q2: The acknowledge bit was not pull low for SDA pin after I2C master write to slave for each ninth clock .
Please kind advice
Thanks
Ping Chen
05-27-2011 08:04 AM
Greetings Ping Chen.
If by "burst write", you mean writing consecutive bytes of data without having to resend a stop bit and address byte(s) repeatedly, then yes this is possible. The "NI-845x I2C Write" VI accepts an array as the input for the "write data" terminal.
I can not be immediately sure as to why you're not seeing the SDA line pulled low on the 9th clock. This is the responsibility of the slave device to acknowledge that it has received the data sent. As such, it seems that something is configured wrong and your slave device is not actually receiving the data it expects.
The below document details the use of the NI-8451 for I2C systems and may be beneficial for troubleshooting your system.
Using I2C with LabVIEW and the USB-8451
http://zone.ni.com/devzone/cda/tut/p/id/5767
Hope this helps!
Regards,
Michael G