Information

• Slave mode
• Module Disable mode
• MCU-specific modes:
• External Stop mode
• Debug mode
The DSPI enters module-specific modes when the host writes a DSPI register. The MCU-
specific modes are controlled by signals external to the DSPI. The MCU-specific modes
are modes that an MCU may enter in parallel to the DSPI block-specific modes.
43.1.4.1 Master Mode
Master mode allows the DSPI to initiate and control serial communication. In this mode,
the SCK signal and the PCS[x] signals are controlled by the DSPI and configured as
outputs.
43.1.4.2 Slave Mode
Slave mode allows the DSPI to communicate with SPI bus masters. In this mode, the
DSPI responds to externally controlled serial transfers. The SCK signal and the PCS[0]/
SS signals are configured as inputs and driven by an SPI bus master.
43.1.4.3 Module Disable Mode
The Module Disable mode can be used for MCU power management. The clock to the
non-memory mapped logic in the DSPI can be stopped while in the Module Disable
mode.
43.1.4.4 External Stop Mode
External Stop mode is used for MCU power management. The DSPI supports the
Peripheral Bus Stop mode mechanism. When a request is made to enter External Stop
mode, the DSPI block acknowledges the request and completes the transfer that is in
progress. When the DSPI reaches the frame boundary, it signals that the system clock to
the DSPI module may be shut off.
Chapter 43 SPI (DSPI)
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 961