CLOCK_RATE_CONVERSION - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// smclib.h
typedef struct _CLOCK_RATE_CONVERSION {
ULONG F;
ULONG fs;
} CLOCK_RATE_CONVERSION, *PCLOCK_RATE_CONVERSION;
View the official Windows Driver Kit DDI referenceNo description available.
The CLOCK_RATE_CONVERSION structure holds a value that determines the duration of a bit of data and the corresponding maximum operating frequency that accompanies the indicated bit length.
FContains a value that calculates the elementary time unit (ETU). The ETU indicates the space of transmission time that is occupied by a single bit of data. For more information, see the ISO 7816-3 Specification.
fsContains the maximum clock frequency that is allowed. For more information, see the ISO 7816-3 Specification.
As stated in the ISO 7816-3 Specification, the operating system defines an array of CLOCK_RATE_CONVERSION structures that determine the maximum operating frequency for a smart card or a smart card reader. The ISO 7816-3 Specification defines a mapping between ETUs and clock frequencies. The following array, defined in Smclib.h, shows the mapping:
static CLOCK_RATE_CONVERSION ClockRateConversion[] = {
{ 372, 4 MHZ },
{ 372, 5 MHZ },
{ 558, 6 MHZ },
{ 744, 8 MHZ },
{ 1116, 12 MHZ },
{ 1488, 16 MHZ },
{ 1860, 20 MHZ },
{ 0, 0 },
{ 0, 0 },
{ 512, 5 MHZ },
{ 768, 7500000 },
{ 1024, 10 MHZ },
{ 1536, 15 MHZ },
{ 2048, 20 MHZ },
{ 0, 0 },
{ 0, 0 }
};