SDReadWriteRegistersDirect (Compact 2013)
3/26/2014
This function reads from or writes to the registers of a secure digital input output (SDIO) card.
Syntax
SD_API_STATUS SDReadWriteRegistersDirect(
SD_DEVICE_HANDLE hDevice,
SD_IO_TRANSFER_TYPE ReadWrite,
UCHAR Function,
DWORD Address,
BOOLEAN ReadAfterWrite,
PUCHAR pBuffer,
ULONG BufferLength
);
Parameters
- hDevice
[in] Handle to a secure digital (SD) bus device.
- ReadWrite
[in] Value that indicates whether to read from or write to the registers of an SDIO card. A value of SD_IO_READ indicates a read operation. A value of SD_IO_WRITE indicates a write operation.
- Function
[in] Function number.
- Address
[in] Starting register address for the read or write operation.
- ReadAfterWrite
[in] Value that indicates whether to perform a read operation following a write operation. If set to TRUE, a read is performed following a write operation. The read data is returned in pBuffer.
- pBuffer
[in, out] Buffer to hold register data.
- BufferLength
[in] Number of bytes to read or write.
Return Value
A return value of type SD_API_STATUS indicates success or failure.
Remarks
Direct I/O is intended for simple register access and requires a significant amount of overhead for each byte transferred. The preferred method for transferring large amounts of data is through the extended I/O command.
Requirements
Header |
sdcardddk.h |
Library |
sdcardlib.lib |