Multi-chip reference counting power management

A payment reader comprising:

• a payment reader system configured to operate a plurality of reader subsystems and a payment application subsystem, the payment reader system comprising a memory device to store a first reference counter and a second reference counter, wherein each of the payment application subsystem and the plurality of reader subsystems is capable of modifying one or more of the first reference counter and the second reference counter;
• a payment processing subsystem in communication with one or more payment interfaces, the payment processing subsystem configured to process payments based on payment information received from the one or more payment interfaces, and the payment processing subsystem in communication with the payment application subsystem;
• a power management subsystem configured to operate the payment reader in one power mode of a plurality of power modes, the plurality of power modes including a first power mode, a second power mode and a third power mode, and wherein, in each of the second power mode and the third power mode, power to one or more of the reader subsystems and the payment processing subsystem is reduced with respect to the first power mode;
• and
• wherein the power management subsystem is configured to transition the power mode of the payment reader from the first power mode to the second power mode based on a value of the first reference counter and from the second power mode to the third power mode based on a value of the second reference counter.

A method for transitioning power modes in a payment reader comprising:

• requesting use of at least one of a payment reader system or a payment processing subsystem by a subsystem of the payment reader system;
• incrementing a first counter in response to the request;
• changing a power mode of the payment reader to a first power mode from a second power mode by a power management system in response to the request, wherein the second power mode uses less power than the first power mode and the first power mode results in power being provided to at least one of the payment reader system or the payment processing subsystem;
• operating the requested at least one of the payment reader system or the payment processing subsystem in the first power mode;
• decrementing the first counter in response to the subsystem completing the use of the requested at least one of the payment reader system or the payment processing subsystem;
• determining if the first counter is equal to zero;
• and
• modifying a power mode of the payment reader from the first power mode to the second power mode in response to the determination that the first counter is equal to zero.