There are 16 reserved I2C addresses. The following table shows the purposes of these addresses:
|I2C slave address||Direction bit (R/W)||Description|
General call address
Reserved for different bus format
Reserved for future purposes
Hs-mode master code
10-bit slave addressing
The general call address is for addressing all devices connected to the I2C bus. If a device does not need the provided data, it can ignore this address (it does not issue the acknowledgement). If a device requires data from a general call address, it acknowledges this address and behaves as a slave-receiver. If one or more slaves acknowledge the general call address, the master does not know how many devices did it and does not see not-acknowledged slaves.
If you use a DLN-series adapter as I2C slave, you can configure it to support general call addressing or to ignore it.