Module State Transitions; Concurrent Power Domain/Module State Transitions - Texas Instruments TMS320C6457 User Manual

Power/Sleep Controller
• Set PDCTL[X].NEXT for an ON (0x1) transition. Note: When PTCMD.GO[X] is set to 0x1 in the next
step, the PDCTL[X].NEXT field of this power domain and the MDCTL[Y].NEXT field of the module in
this power domain are evaluated. Therefore, you may set the MDCTL[Y].NEXT field for multiple
modules before executing this step. Note that, if enabling other modules, ensure that if they are not in
the AlwaysOn domain, the memories for that module are not asleep.
• Set PTCMD.GO[X] to 0x1 to initiate the state transition(s). The PSC awakens the memory for that
particular domain.
• Wait for PTSTAT.GOSTAT[X] to clear to 0x0. The domain is safely in the new state only after
PTSTAT.GOSTAT[X] is cleared to 0x0.
2.3.2

Module State Transitions

This section describes the procedure for transitioning the module state.
Note: In the C6457 device, the following procedure is directly applicable for all LPSC-controlled
modules, except the C64x+ core domains. To transition the module state, you must be aware
of several system considerations. Transitions from Enable to any other state are not allowed.
Also, before transitioning a module to Enable, if the memories are not in the AlwaysOn
power domain, they must be turned on before or in parallel with the transition. See
Section
The procedure for module state transitions follows (X denotes the power domain number, Y denotes the
module domain number):
• Wait for PTSTAT.GOSTAT[X] to clear to 0x0. Wait for any previously initiated transitions to finish
before initiating a new transition.
• Set MDCTL[Y].NEXT to Enable (0x3). Note that you may set transitions in multiple MDCTL[Y].NEXT
fields in this step as long as the corresponding power domain is on.
• Set PTCMD.GO[X] to 0x1 to initiate the transition(s).
• Wait for PTSTAT.GOSTAT[X] to clear to 0x0. The module is safely in the new state only after
PTSTAT.GOSTAT[X] clears to 0x0.
2.3.3

Concurrent Power Domain/Module State Transitions

This section describes the basic procedure for transitioning the state of a power domain and module
domain for modules which are not in the AlwaysOn domain. You may do these separately as described in
the sections above, if desired.
The procedure for concurrent power domain/module state transitions follows (X denotes the power domain
number, Y denotes the module domain number):
• Wait for PTSTAT.GOSTAT[X] to clear to 0x0. Wait for any previously initiated transitions to finish
before initiating a new transition.
• Set PDCTL[X].NEXT for an ON (0x1) transition.
• Set MDCTL[Y].NEXT to Enable (0x3). Note that you may set transitions in multiple MDCTL.NEXT
fields in this step as long as the corresponding power domain is on.
• Set PTCMD.GO[X] 0x1 to initiate the state transition(s). The PSC awakens the memory for that
particular domain, starts the module clock, then de-asserts the module reset.
• Wait for PTSTAT.GOSTAT[X] to clear to 0x0. The domain is safely in the new state only after
PTSTAT.GOSTAT[X] is cleared to 0x0.
10 TMS320C6457 DSP Power/Sleep Controller (PSC)
2.3.1.
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SPRUGL4 – March 2009
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