초록 ▼

A data-storing token includes a microprocessor which responds to a signal generated by a token interrogator for altering its clock frequency so as to achieve synchronization between the token and interrogator operations. Additional synchronization is achieved by adjusting the length of delay loops i

A data-storing token includes a microprocessor which responds to a signal generated by a token interrogator for altering its clock frequency so as to achieve synchronization between the token and interrogator operations. Additional synchronization is achieved by adjusting the length of delay loops in routines used for communication between the token and the interrogator.

대표청구항 ▼

A data-storing token which can perform a communication operation involving at least one of transmitting and receiving data in a contactless manner ussing an externally generated signal, said token comprising: a clock generator for generating clock pulses, the clock generator including frequency adju

A data-storing token which can perform a communication operation involving at least one of transmitting and receiving data in a contactless manner ussing an externally generated signal, said token comprising: a clock generator for generating clock pulses, the clock generator including frequency adjustment means for adjusting the frequency of the clock pulses in response to a frequency adjustment signal; and a processor arranged for receiving the clock pulses so as to operate at a rate dependent on the frequency of the clock pulses, said processor being arranged to execute a synchronization operation prior to the communication operation, the processor being responsive during the synchronization operation to the externally generated signal for producing the frequency adjustment signal, the frequency adjustment signal being such as to cause the clock frequency to approach a substantially predetermined relationship with the frequency of the externally generated signal, thereby to allow a subsequent synchronized communication operation to occur.