UR8HC007-001 Datasheet, PDF (10/18 Pages) Semtech Corporation – Input Device and Power Management Companion IC for Jupiter Devices

POWER MANAGEMENT MODES OF OPERATION
The UR8HC007 has three modes of
operation relating to its power
consumption.
POWER MANAGEMENT
The Juno™ UR8HC007 family of controllers implements two power
management methods: system-coordinated power management and Self
Power Management™ (SPM).
The "Stop" mode is the lowest
power consumption mode. In this
mode, the crystal is stopped and
the IC consumes only 1 µA of
leakage current. This is the default
mode to which the IC will revert any
time an event or a signal condition
does not force it to exit this mode.
The "Wait" mode is entered each
time it is necessary for a timer to be
running in order to perform a
system function. Such functions
include the LED blinking mode and
the use of one of the PWM
channels. Typical power
consumption in this mode is several
hundred µAs.
System-coordinated power management primarily determines the tasks
performed and the type of reports communicated to the Host. The Juno™
monitors the system states through the PWROK (Power OK), _LID (Lid
closed) and _HSUS (Host suspended) lines. In addition to these signal
inputs, the UR8HC007 family provides a set of registers, described in the
"Registers" chapter of the Juno^TM Technical Reference Manual, that can be
used by the host to control the PM-related performance of the controller
through software. According to the status of these lines (or register
settings), the Juno™ will enable or disable specific tasks and reports suited
to the current power and system management state of the Host.
Self Power Management™ describes a method implemented by the Juno™
controller that, independently of any system intervention, results in the
lowest power consumption possible within the given parameters of its
operation. Through Self Power Management™, the Juno™ controllers are
capable of typically operating at only 1 µA, independent of the state of the
system. Self Power Management™ primarily determines the actual power
consumption of the controller IC.
The "Run" mode is entered briefly,
only to process an event or while an
interrupt-generating signal condition
persists. The controller IC will
remain in this mode only for as long
a signal prohibits it from reentering
a lower power consumption mode
or for as long as it is necessary to
process a Host-related transaction
(a few milliseconds).
The Juno™ implements the Semtech-patented Self Power Management™
method to achieve the minimum power consumption possible, independent
of the Host power management state.
Even when the Host is in the active state, the IC can still operate most of the
time at only 1 µA, even with external PS/2 devices attached to it.
Critical
Suspend
PWROK=0
PWROK=0
PWROK=1
AND
_LID=0
PWROK=1
AND _LID=1
AND _HSUS=1
PWROK=1
AND _LID=1
AND _HSUS=0
PWROK=1
AND _LID=0
Lid
Closed*
PWROK=0
PWROK=1
AND _LID=1
AND _HSUS=1
Host
Suspend
PWROK=1
AND _LID=1
AND _HSUS=0
PWROK=1
AND _LID=0
PWROK=1 AND _LID=1 AND _HSUS=1
PWROK=1 AND _LID=1
AND _HSUS=0
SPM
Figure 2: USAR Juno^TM State Diagram
Copyright ©1998-2001 Semtech Corporation
10
DOC8-007-001-DS-108
www.semtech.com