Buffer Status; Interrupt; Dma Request - Holtek HT32F12345 User Manual

32-Bit Arm ® Cortex ® -M3 MCU
HT32F12345

Buffer Status

The SDIO contains an 8 × 32-bit data buffer shared by both data read and write operations. The
buffer level can be checked by reading the BLSTA field in the Present State Register and the data
can be read from or written into the buffer by accessing the Data Port Register.
Once the buffer contains 4 × 32-bit data in a read operation or the buffer has 4 × 32-bit space in a
write operation, the BHSTA bit in the Status Register will be set. When the FIFO is full or empty,
the BFSTA or BESTA bit in the Status Register will be set. All the buffer status flags can be
enabled by setting the corresponding bits in the Status Enable Register.

Interrupt

The SDIO can issue a buffer half full, buffer full or buffer empty interrupt to the NVIC if the
corresponding enable bit in the Interrupt Enable Register is enabled.
The Card Interrupt Request sent from the device to the host can be checked by reading the CISTA
bit in the Status Register if the corresponding bit in the Status Enable Register is enabled.

DMA Request

If the buffer is empty during a write operation or if the buffer contains more than 4 × 32-bit data
during a read operation, the SDIO will send a DMA request to the PDMA if the DMAEN bit in the
Transfer Mode Register is set.
Table 81. SDIO Command Register Fields and Values
Command
CMD0
CMD2
CMD9
CMD10
CMD1
CMD3
CMD5 (Note)
CMD7
CMD8
CMD12
CMD13
CMD16
CMD32
CMD33
CMD38
CMD52 (Note)
CMD55
ACMD6
ACMD23
ACMD41
Rev. 1.10
Abbreviation
GO_IDLE_STATE
ALL_SEND_CID
SEND_CSD
SEND_CID
SEND_OP_COND
SEND_RELATIVE_ADDR
IO_SEND_OP_COND
SELECT/DESELECT_CARD
SEND_IF_COND
STOP_TRANSMISSION
SEND_STATUS
SET_BLOCKLEN
ERASE_WR_BLK_START
ERASE_WR_BLK_END
ERASE
IO_RW_DIRECT
APP_CMD
SET_BUS_WIDTH
SET_WR_BLK_ERASE_COUNT
SD_SEND_OP_COND
571 of 590
Fields and Values
RESP_TYPE = 0 No response
DAT_PRESENT = 0 operation
RESP_TYPE = 1 Long response
DAT_PRESENT = 0 operation
RESP_TYPE = 2 Short response
DAT_PRESENT = 0 operation
November 28, 2018
Description