USB2524 datasheet(42/58 Pages) MICROCHIP

42 / 58 page

USB2524

DS00001588B-page 42

 2013 - 2016 Microchip Technology Inc.

LED_Bx_N Driven to Logic Low = Port Owned by Host “B” and is operating at USB LS/FS Speed

LED_Bx_N Driven to Logic High = Port Owned by Host “B” and is operating at USB HS Speed

LED_Bx_N Pulsed @ 1KHz= Port Owned by Host “B” and has nothing attached.

LED_Bx_N is tri-state= LED “B” is off.

If a Port is disabled, or is Unassigned, then neither the “A” or “B” LED associated with that port will be asserted (i.e. both

LED's will be OFF/tri-stated).

Since these LED’s are provided to give an end-user a clear indication of Host Ownership of downstream ports, they will

function when the hub is in suspend, and will indicate Host ownership even if the applicable assigned Host is discon-

nected, powered off, etc.

When a downstream device is in suspend (or the Hub is in suspend), connected devices will continue to reflect the

proper LED color for the operational speed the device is enumerated at (i.e, HS will remain HS, and FS/LS will remain

FS/LS) What will change is the 3rd color which represents an assigned port with no connection, when in suspend the

corresponding LED will be off (giving the same indication as unassigned, while the hub is suspended). This disables the

1khz toggle while the hub is suspended.

USB2524 数据表(PDF) 42 Page - Microchip Technology