15.1 Typical SPI Configurations
15.1.1 Single Master & Single Slave
For the master: any port pin, including P1.4 (/SS), can be used to drive the /SS pin of the slave.
For the slave: SSIG is ‘0’, and /SS pin is used to determine whether it is selected.
Figure 15-2. SPI single master single slave configuration
15.1.2 Dual Device, where either can be a Master or a Slave
Two devices are connected to each other and either device can be a master or a slave. When no SPI operation is
occurring, both can be configured as masters with MSTR=1, SSIG=0 and P1.4 (/SS) configured in quasi-
bidirectional mode. When any device initiates a transfer, it can configure P1.4 as an output and drive it low to
force a “mode change to slave” in the other device. (See Section 15.5: Mode change on /SS-pin)
Figure 15-3. SPI dual device configuration, where either can be a master or a slave
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MPC82G516A Data Sheet
MEGAWIN
MEGAWIN [ MEGAWIN TECHNOLOGY CO., LTD ]
