AMIS-30522 Datasheet, PDF (20/29 Pages) AMI SEMICONDUCTOR – Micro-stepping Motor Driver

AMIS-30522
Figure 19: Single WRITE operation where DATA from the Master is written in SPI register with Address 3
9.2.3. Examples of combined READ and WRITE operations
In the following examples successive READ and WRITE operations are combined. In Figure 18 the Master first reads the status
from Register at ADDR4 and at ADDR5 followed by writing a control byte in Control Register at ADDR2. Note that during the write
command (in Figure 4) the old data of the pointed register is returned at the moment the new data is shifted in
Figure 20: 2 successive READ commands followed by a WRITE command
After the write operation the Master could initiate a read back command in order to verify the data correctly written as illustrated in
Figure 19. During reception of the READ command the old data is returned for a second time. Only after receiving the READ
command the new data is transmitted. This rule also applies when the master device wants to initiate an SPI transfer to read the
Status Registers. Because the internal system clock updates the Status Registers only when CSB line is high, the first read out
byte might represent old status information.
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