Q: Is it possible to receive a list of all I²C-slave addresses used to date?
A: No. NXP Semiconductors do not issue this list of all previously assigned slave addresses, as this is the only way we can guarantee the list stays up to date and each assigned address is unique. If this list were made available, I²C-bus licensees would start selecting slave addresses themselves and the central list would soon become incomplete, which could lead to address conflicts. The principle established, proven to work well, is that each licensee sends a slave address request to a single contact within NXP Semiconductors, who then allocates the slave address based on a single master list.

Q: If the slave address is the same as the one allocated to a previous IC, must an address allocation fee be paid again?
A: No. No extra costs are charged.

Q: If I send information on a new IC, which may be confidential, will NXP guarantee that this information is not copied?
A: Yes. All information received for address allocation is treated as completely confidential and is never duplicated or disseminated in any way.

Q: What is the benefit of using the programmable address bits?
A: The use of one or more programmable address bits will reduce the chance of an address conflict on the I²C-bus. When the IC can be used in different application fields, like TVs, VCRs, mobile phones, they are candidates. Examples are the EEPROM memories. You will get a notification when it applies to the new IC.

Q: Do I have to pay for each programmable address bit?
A: No. No extra costs are charged.

Q: When to use 10-bit addresses?
A: If possible a 10-bit address is advised for new types of ICs. The reason is that the short of the 7-bits address allocations make it more and more difficult to allocate a non-conflicting address. Examples are: display screen controllers, camera signal processing, mobile phone related ICs.

Q: How important is the type number?
A: The type number is used to identify the IC in the address database. It is to be used as an answer to the questions: "Slave address must be identical to device:" and "Slave address must not be identical to devices:".

Q: How important is the additional information?
A: The additional information should indicate which functionalities are available on the IC and in what kind of application the IC will be used. This will help us to understand what other ICs (functionalities) may be present on the same I²C-bus.