
6
7409 Restrictions for USB Devices if Using S3 Standby
IfS3Standbystateisdesired,therearecertainrestrictionswithconnectingtheMSRto
a7409terminal.
Restrictions on 7409 USB Ports:
If a Restricted Device is
plugged into Port: An S3 Wake Device can
NOT be plugged into Port:
AB
BA
CD
DC
EF
FE
Note: TherestrictionsonlyapplyifitisdesiredtoputtheunitinS3standbystate.
USB Devices Capable of Waking the 7409 from an S3 State
•USBKeyboard
•USBMouse
Reasons for the Restrictions
•USBportsshareUHCIhostcontrollersintheSouthbridge.
•AllexternalUSBportsonthe7409arepoweredby5VSBandkeptONduringS3
Standby.
•SomeUSBperipheralsarepoweredbytheRS‐232port(either5Vor12V).
Ways Around the Issue
•AdheretotheRestrictionGuidelinesprovidedabove.
•InWindows,disabletheS3WakeDevice’sabilitytowaketheunitfromStandby.
•PowertheRestrictedDevicesfromanexternalpowersourceinsteadoftheRS‐232
ports.