User Manual

SPI Protocol Definition
5-12 TriFlash with SD Interface Product Manual (Preliminary), Rev. 1.2 © 2002/2003 SANDISK CORPORATION
5.2.3. Responses
There are several types of response tokens. As in the SD Bus mode, all are transmitted MSB first.
5.2.3.1. Format R1
This response token is sent by the device after every command with the exception of SEND_STATUS commands. It
is 1 byte long, the MSB is always set to zero and the other bits are error indications. A ‘1’ signals error.
The structure of the R1 format is given in Figure 5-7.
• In idle state: The device is in idle state and running initializing process.
• Erase reset: An erase sequence was cleared before executing because an out of erase sequence
command was received.
• Illegal command: An illegal command code was detected.
• Communication CRC error: The CRC check of the last command failed.
• Erase sequence error: An error in the sequence of erase commands occurred.
• Address error: A misaligned address, which did not match the block length was used in the command.
• Parameter error: The command’s argument (e.g., address, block length) was out of the allowed range
for this device.
7
In Idle State
Erase Reset
Illegal Command
Com CRC Error
Erase_Seq_Error
0
0
Address Error
Parameter Error
Figure 5-7. R1 Response Format
5.2.3.2. Format R1b
This response token is identical to R1 format with the optional addition of the busy signal. The busy signal token
can be any number of bytes. A zero value indicates device is busy. A non-zero value indicates device is ready for
the next command.
5.2.3.3. Format R2
This 2-bytes long response token is sent by the device as a response to the SEND_STATUS command. The format
of the R2 status is given in Figure 5-8.