USB2524 datasheet(41/58 Pages) MICROCHIP

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DS00001588B-page 41

USB2524

Figure 8-1 shows a simple example of how this LED circuit will be implemented. The Circuit will need to be replicated

for each of the 8 LED pins on the USB2524. In this circuit, when the LED pin is driven to a logic low state, the Green

LED will Light up. When the LED pin is driven to a Logic High state the Red LED will Light up. When a 1KHz square

wave is driven out on the LED pin, the Green and Red LED’s will both alternately light up giving the effect of the color

Orange. When nothing is driven out on the LED pin (i.e. the pin floats to a “tri-state” condition), neither the Green or Red

LED will light up, this is the “Off” state.

The assignment is as follows:

LED_A1_N = Port 1 Owned By Host A

LED_B1_N = Port 1 Owned By Host B

LED_A2_N = Port 2 Owned By Host A

LED_B2_N = Port 2 Owned By Host B

LED_A3_N = Port 3 Owned By Host A

LED_B3_N = Port 3 Owned By Host B

LED_A4_N = Port 4 Owned By Host A

LED_B4_N = Port 4 Owned By Host B

The Usage is as follows:

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

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

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

LED_Ax_N is tri-state= LED “A” is off.

TABLE 8-1:

DUAL COLOR LED IMPLEMENTATION EXAMPLE

LED pin

Green LED

Red LED

3.3V

General

Purpose

Diode

Current limiting

resistor

Connect to other

dual color diodes.

USB2524 Arkusz danych(PDF) 41 Page - Microchip Technology