Hi All,
I am wondering if anyone has tried interfacing the CDCE906 device to a Cypress CY7C68013 USB device
I2C bus? The data sheet states the SMBus is based on I2C but what are the differences.
I am comparing a CDCE906 against a CDCE937 and CDCE925.
I am unable to communicate with the CDCE906 on the I2C bus but both the other devices work fine.
I am wondering if there is some subtle difference between the 906 SMBus and the I2C bus on the other devices?
All the devices are on similar plug in boards connecting to a common Cypress CY7C68013 USB chip SDA and SCL pins.
I have already increased the pull-up resistors on the I2C bus from 2k2 to 10K to the 3.3V rail, to conform to the 350uA
maximum current for the SMBus, but this made no difference.
I am supplying the 906 from a single 3.3V supply the same as that used for the other devices with the 1.8V supply not used for the 906.
Both pins 1 and 2 (S0 and S1) are tied high and I am addressing the device as 0x69 and 0x6D for the CDCE937 which works.
I notice on the data sheet for the CDCE906, page 11 shows Read (bit0) as active low! as page 12 shows it as active high like the CDCE937
I am assuming that this is an error in the 906 data sheet?
Thanks!
Martin.
