Mpui Port Modes - Texas Instruments OMAP5910 Reference Manual

9.2.1

MPUI Port Modes

SPRU890A
For complete information on these registers, see the OMAP5910 Dual-Core
Processor MPU Subsystems Reference Guide (SPRU671) and the
OMAP5912 Multimedia Processor OMAP3.2 Subsystem Reference Guide
(SPRU749).
The MPUI port supports two access modes for the DSP subsystem internal
memory:
Shared-access mode for internal memory (SAM_M). The DSP subsystem
-
SARAM and DARAM are shared between the DSP domain and the MPU
domain.
Host-only mode for internal memory (HOM_M). In this mode, the MPU
-
domain can only access SARAM. However, it can completely lock out the
DSP controllers from a portion of the SARAM. The API_SIZE bits in the
MPUI_DSP_CONFIG register specify the amount of SARAM that is
dedicated to MPU domain accesses.
Similarly, the MPUI port supports two access modes for DSP subsystem
peripherals on the DSP public peripheral bus:
Shared-access mode for peripherals (SAM_P). The peripherals on the
-
DSP public peripheral bus are shared between the DSP controllers and
the MPU domain.
Host-only mode for peripherals (HOM_P). The MPU domain has exclusive
-
access to the peripherals on the DSP public peripheral bus.
SAM_M and SAM_P are the normal operating modes in which all the DSP
subsystem internal memory and the public peripherals are accessible by the
MPUI controllers, as well as the DSP controllers. When the DSP subsystem
is taken out of reset, SAM_M and SAM_P are invoked automatically. In
SAM_M, if both the DSP controllers and the MPU controllers access the same
memory at the same time, priority is given to the DSP controllers. An MPU
controller access in SAM_M is synchronized to the internal DSP core clock,
which can add access latency to transfers.
HOM_M and HOM_P provide the MPU controllers with exclusive access to the
DSP subsystem SARAM or public peripherals, primarily to support high-speed
transfers from or to the DSP domain during DSP subsystem reset or IDLE
conditions. When the DSP subsystem is placed in reset, HOM_M and HOM_P
are invoked automatically. In HOM_M, the MPUI interface does not have
access to the DARAM, but it has access to all of SARAM. Additionally, only the
MPU controllers can access the DSP public peripheral bus in HOM_P.
MPU Interface Port
DSP Subsystem 195