Length-variable multi-block data transmission method of memory card

Abstract

The memory card length changeable multi block data transmission comprises the reading card to allow the memory card to go into the side setting status, sending orders to the memory card to make it going into the transmission status, in which the reading card sets multi blocks of data transmission quantity through order setting. It also comprises adding several blocks length changing data order to the memory transmission order list to finish the reading and writing of the data when the configuration of the data transmission is over. It is flexible and convenient in improving the transmission efficiency.

Description

technical field [0001] The invention relates to a memory card data transmission method, in particular to a memory card variable-length multi-block data transmission method. Background technique [0002] When an ordinary memory card such as MMC / SD card transmits a large amount of data between the card reader and the card reader, multiple data transfer operations can be performed between the card reader and the memory card. The data transfer operation includes multi-block data reading and multi-block Data writing, the process state transition diagram is as follows figure 1 shown. If the card reading device wants to complete a large amount of data transmission with the memory card, the memory card can be made to enter the side state 110, and when the memory card enters the side state 110, the card reader sends the CMD7 command 120 to the memory card to make the memory card enter Transmission state 130, in the transmission state 130, the card reading device can set the data bl...

AI Technical Summary

Problems solved by technology

If the length of the data block in step 2) is set to be 1514Byte long, although the data transmission can be completed through two block transmissions, the length of each data block is 1514Byte long, which wastes a lot of time in the entire data transmission process. (1514-64)*8=11600 clock cycles

From the above process, we can see that if the card reader wants to transmit a 64Byte small packet and a 1514Byte large packet to the memory card, it needs to split the two data packets into four 512Byte data blocks in advance. , and then it can be transmitted; similarly, the same process must be experienced in the process of retransmission, so the processing speed of the data will be reduced in the process of splitting and assembling these data; if the block length is set to be longer Large and the transmission speed will be greatly reduced due to the waste of the transmission clock cycle

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