EAGLE
PRELIMINARY
Ver 1.3
3.11.3.1 No Response and No Data Operations
The above figure shows the typical transaction for command and response. Response token may or may not be generated
depending on the type of command token. If response token is expected from SD Card, SD Controller shall wait until the
waiting time limit. If time limit is reached and response token is not transmitted, controller will generate a time out error.
Detailed specification on command token is well described in SD card spec v1.10.
3.11.3.2 Data Read Operation
This figure shows the transaction for Data read operation. When read command is transmitted from controller to SD Card,
SD Card replies with a response and data token in unit block(token). The size of one block is 512 bytes. When all data has
been received by controller, controller sends a stop command to stop the read operation. Similar to response token, controller
will generate a time out error if data is not received within a wait time limit.
3.11.3.3 Data Write Operation
This figure shows the transaction for data write operation. If controller receives a response successfully after sending a
write command, the first data block will be transmitted. The following data block is transmitted after controller checks and
confirms the busy signal. As the busy signal checking procedure is done by hardware, user may write data whenever storage
space is available in data buffer.
Beijing Peak Microtech Co.Ltd.
CONFIDENTIAL
114
ETC [ ETC ]
