Patent ID: 8677145

Claim:
A battery pack comprising: a battery; and a communication chip coupled to the battery, the communication chip including: a communication pin to couple the communication chip to another device to exchange data; a communication circuit coupled to the communication pin, and to detect and count pulses serially received or transmitted on the communication pin corresponding to a wake token, a zero token and a one token, wherein the zero token comprises a first low pulse occurring for a start period, followed by a first high pulse occurring for a high period, followed by a second low pulse occurring for a low period, and wherein the one token comprises the second low pulse followed by a second high pulse that is sent after the start period, and wherein the communication circuit uses pulse counts to transfer data; a memory containing secret data and a serial number of the battery pack; a command circuit to perform cryptographic calculations utilizing the secret data to authenticate the battery pack, wherein the command circuit is coupled to the communication circuit to receive commands and provide data responsive to such commands; and a third circuit to assemble zero and one tokens into one or more bytes for providing responses verifying proper command executions, including one of cryptographically calculated data based on the secret data, cryptographically calculated data based on a received digest, or cryptographically calculated data based on a customer identification data.