DescriptionbLength1Total length of the CCID descriptorbDescriptorType1CCID descriptor type (21h)bcdCCID2CCID specification release number in Binary Coded Decimal (BCD) format.bMaxSlotIndex1Index of the highest available slot.bVoltageSupport1What voltages the CCID can supply to its slotsdwProtocols4Supported protocol types46348AATARM06-Jul-09Application Note4.2.4Class-specific Requests4.2.4.1GetDescriptorWhile GET_DESCRIPTOR is a standard request (defined in the USB specification 2.0), newdescriptor type values have been added for the CCID class. They make it possible for the host torequest the CCID descriptor, ABORT descriptor, GET_CLOCK_FREQUENCY descriptor andGET_DATA_RATES descriptor used by the device.When requesting a CCID-specific descriptor, the wIndex field of the request must be set to theCCID interface number. For standard requests, this field is either set to 0 or, for String descrip-tors, to the index of the language ID used.4.3Host DriversMicrosoft class CCID driver is use features or capabilities. Please refer tothe CCID specifications for more information.4.2.3.1CCID DescriptorThe CCID descriptor gives information about the CCID specification revision used, the countryfor which a device is localized, and lists the number of class-specific descriptors, including theirlength and type. The format is described in Table 4-1. HOSTControl 0Bulk INBulk OUTInterrupt INConfigurationISO 7816Smart CardTPDUDEVICETable 4-1.CCID Descriptor FormatFieldSize (bytes)DescriptionbLength1Total length of the CCID descriptorbDescriptorType1CCID descriptor type (21h)bcdCCID2CCID specification release number in Binary Coded Decimal (BCD) format.bMaxSlotIndex1Index of the highest available slot.bVoltageSupport1What voltages the CCID can supply to its slotsdwProtocols4Supported protocol types46348AATARM06-Jul-09Application Note4.2.4Class-specific Requests4.2.4.1GetDescriptorWhile GET_DESCRIPTOR is a standard request (defined in the USB specification 2.0), newdescriptor type value specification in order to provide a standard m