Deserial Serial Peripheral Interface (DSPI)
MPC5510 Microcontroller Family Reference Manual, Rev. 1
23-4
Freescale Semiconductor
Preliminary
23.1.3
Modes of Operation
The DSPI has four modes of operation that can be divided into two categories: block-specific modes and
an MCU-specific mode. Master mode, slave mode, and module disable mode are the block-specific modes,
and debug mode is the MCU-specific mode.
The block-specific modes are entered by host software writing to a register bit. The MCU-specific mode
is selected by a signal external to the DSPI. The MCU-specific mode is a mode that the MCU may enter
in parallel to the DSPI being in one of its block-specific modes.
23.1.3.1
Master Mode
Master mode allows the DSPI to initiate and control serial communication. In this mode the SCK, PCS,
and SOUT signals are controlled by the DSPI and configured as outputs.
23.1.3.2
Slave Mode
Slave mode allows the DSPI to communicate with SPI/DSI bus masters. In this mode the DSPI responds
to externally-controlled serial transfers. The DSPI cannot initiate serial transfers in slave mode.
23.1.3.3
Module Disable Mode
The module disable mode is used for MCU power management. The clock to the non-memory-mapped
logic in the DSPI is stopped while in module disable mode. The DSPI enters the module disable mode
when the MDIS bit in DSPI_MCR is set.
23.1.3.4
Debug Mode
Debug mode is used for system development and debugging. If the device enters debug mode while the
DSPI_MCR[FRZ] bit is set, the DSPI halts operation on the next frame boundary. If the device enters
debug mode while the FRZ bit is negated, the DSPI behavior is unaffected and remains dictated by the
block-specific mode and configuration of the DSPI.
23.2
External Signal Description
Refer to
Section 2.7, “Detailed External Signal Descriptions
,” for detailed signal
descriptions.
23.3
Memory Map and Registers
This section provides a detailed description of all DSPI registers.
23.3.1
Module Memory Map
The DSPI memory map is shown in
(the memory map is the same for each individual DSPI
module). The address of each register is given as an offset to the DSPI base address. Registers are listed
in address order, identified by complete name and mnemonic, and list the type of accesses allowed.