Arm
®
CoreLink™ GFC-200 Generic Flash Controller
Technical Reference Manual
Document ID: 101484_0000_01_en
Issue: 01
Functional Description
3.2.6 Q-Channel interface for clock
The Q-Channel interface for clock is a control port for managing the system clock.
GFC-200 can accept or deny a request from the clock controller to turn off all operations that are
using the clock.
Activity indication
GFC-200 uses the
qactive_clk
signal to indicate when any ongoing activity requires the clock.
When GFC-200 asserts
qactive_clk
, the clock controller must keep the clock enabled.
Accepting a request
When GFC-200 has no activity, it accepts the quiescence request for the clock, and enters the
Q_STOPPED state.
Denying a request
When the clock controller requests the clock to be disabled, if there is any ongoing activity in the
GFC-200 then it denies the request.
Related information
3.2.7 Q-Channel interface for power
The Q-Channel interface for power is a control port for managing the system power.
The GFC-200 can accept or deny a request from an external
Power Policy Unit
(PPU) to turn off all
operations that are using power.
Activity indication
The GFC-200 uses the
qactive_pwr
signal to indicate when any ongoing activity requires power.
When GFC-200 asserts
qactive_pwr
, the PPU must keep the power enabled.
Accepting a request
When the GFC-200 or the embedded Flash is inactive, the GFC-200 accepts the quiescence
request for power and enters the Q_STOPPED state. The GFC-200 requests the process-specific
part PCSM to enter the powerdown or full-retention state. If the PCSM accepts the request, then
the GFC-200 accepts the Q-Channel request.
Denying a request
When the PPU requests power to be disabled, if there is any ongoing activity in the GFC-200 then
it denies the request.
Related information
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