Multi-Slot Card Reader Using Standard CCID Protocol
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Solution Overview
Problem
Existing card readers with multiple slots using private CCID drivers face compatibility issues due to non-standard protocols, limiting their functionality and interoperability with hosts.
Innovation Solution
A working method for a card reader with multiple slots based on standard CCID protocol, where the card reader initializes and connects to a host via USB, manages configuration information, and uses distinct end-points for each slot to ensure compatibility and efficient communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a private CCID driver is used to implement multiple slots in a card reader, then the card reader can achieve multiple slot functionality, but compatibility issues arise due to non-standard protocols
Solution Approach 1:
The patent divides the card reader into multiple independent virtual card readers, each corresponding to a physical card slot. Each virtual card reader operates as an independent CCID device with its own endpoint, allowing the system to maintain multiple slot functionality while ensuring standard compliance and compatibility for each individual slot.
Solution Approach 2:
The patent makes a single physical card reader serve multiple functions by creating multiple virtual CCID instances from one physical device. This allows the card reader to function as multiple standard one-slot card readers simultaneously, achieving both multiple slot capability and standard compatibility.
2Reliability
If multiple standard CCID one-slot card readers are emulated in one device, then compatibility is improved, but device complexity increases
Solution Approach 1:
The patent introduces a driver layer as an intermediary between the host and the physical card slots. This driver creates virtual CCID instances that manage the complexity of multiple slots, presenting a standardized interface to the host while handling the underlying complexity of multiple physical slots and their respective protocols.
Data Source
AI summary
A working method of a multi-slot card reader based on the standard CCID protocol comprises: powering up to perform initialization, and establishing a connection with a host through a USB interface; when a USB configuration instruction is received, returning configuration information of the USB interface to the host; waiting to receive an instruction delivered by the host, when a flag bit of a reset is detected, determining the type of the flag bit of the reset, for example, if the flag bit is a contact card flag bit, recording, according to the type of a change of a card placement pin level of a current contact card slot, a corresponding state of the contact card slot, or for example, if the flag bit is a periodic flag bit, sending a card search instruction corresponding to a current non-contact card slot, and recording a corresponding state of the non-contact card slot; and if the flag bit is a USB flag bit, performing a corresponding operation on a current card slot according to the received instruction. The card reader adopts a USB chip having multiple terminations and serves as a composite device of the standard CCID. When accepting access of a host, the card reader access different card slots through different terminations, so that the compatibility is desirable.