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Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
issued in other bus configuration.
The maximum clock frequency for streaming write operations is calculated by the formula given below:
𝑀𝑎𝑥_𝑊𝑟𝑖𝑡𝑒_𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑒 = 𝑀𝑖𝑛(𝑇𝑅𝐴𝑁_𝑆𝑃𝐸𝐸𝐷,
8 × 2
𝑊𝑅𝐼𝑇𝐸_𝐵𝐿_𝐿𝐸𝑁
− 100 × 𝑁𝑆𝐴𝐶
𝑇𝐴𝐴𝐶 × 𝑅2𝑊_𝐹𝐴𝐶𝑇𝑂𝑅
)
Max_Write_Frequence: maximum write frequency
TRAN_SPEED: Maximum bus clock frequency
WRITE_BL_LEN: maximum write block length
NSAC: Data read operation time in CLK cycles 2
TAAC: Data read operation time 1
R2W_FACTOR: Write speed factor
All parameters are defined in CSD registers. If the host attempts to use a higher frequency, the card may not be able
to process the data and stop programming while setting the error bit SDIO_STS.RXORERR in the status register and
ignoring all subsequent data transfers, waiting (in the receive data state) for a stop command . If the host attempts to
write a value in the write-protected area, the write operation will be aborted and the card will set the
WP_VIOLATION bit.
Data stream read
Data Streaming Data transfer is controlled by the READ_DAT_UNTIL_STOP (CMD11) command.
This command requires the card to read data from the specified address until the SDIO card host sends a
STOP_TRANSMISSION (CMD12) command. Due to the delay of serial command transmission, the execution of
the stop command will have a certain delay, so the data transfer will not stop until the end bit of the stop command.
If the host provides an out-of-range address as a parameter to pass to CMD11, the card will reject the command and
stay in the transfer state, the SDIO card host does not send a stop command, and the subsequently transferred data is
also considered invalid data.
Another point to note is that the data stream read command only works in 1-bit bus mode (SDIO_DAT0 signal line).
If CMD11 is issued in other bus configurations, the command is considered illegal.
The maximum clock frequency for stream read operations can be calculated as:
𝑀𝑎𝑥_𝑅𝑒𝑎𝑑_𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑒 = 𝑀𝑖𝑛(𝑇𝑅𝐴𝑁_𝑆𝑃𝐸𝐸𝐷,
8 × 2
𝑅𝐸𝐴𝐷_𝐵𝐿_𝐿𝐸𝑁
− 100 × 𝑁𝑆𝐴𝐶
𝑇𝐴𝐴𝐶 × 𝑅2𝑊_𝐹𝐴𝐶𝑇𝑂𝑅
)
Max_Read_Frequence: maximum read frequency
TRAN_SPEED: maximum data transfer rate
READ_BL_LEN: maximum read data block length
NSAC: Data read operation time in CLK cycles2
TAAC: Data read operation time 1
R2W_FACTOR: Write speed factor
If the host tries to use a higher frequency, the card will not be able to process the data transfer, at this time the card