ADDRESS PACKETS WITH VARIABLE-SIZE MASK FORMAT

A system may include a device configured to initiate a transaction by sending an address packet and an additional device configured to respond to the address packet. The additional device is coupled to receive the address packet from the device via an address network. The address packet includes a mask field configured to indicate which of N quantities of data are targeted by the transaction. The address packet also includes a granularity field configured to indicate a size of each of the N quantities of data. If the size is less than a maximum size, a portion of the granularity field stores additional address bits of an address of the N quantities of data. If the size is the maximum size, none of the granularity field stores any additional address bits of the address of the N quantities of data.