SNLS614A September 2018 – December 2018 DP83869HM
The DP83869HM supports three configurable Light Emitting Diode (LED) pins: LED_0, LED_1, and LED_2. Several functions can be multiplexed onto the LEDs for different modes of operation. The LED operation mode can be selected using the LEDS_CFG1 register (address 0x0018).
Because the LED output pins are also used as straps, the external components required for strapping and LED usage must be considered to avoid contention. Specifically, when the LED outputs are used to drive LEDs directly, the active state of each output driver is dependent on the logic level sampled by the corresponding AN input upon power up or reset.
If a given strap input is resistively pulled low then the corresponding output is configured as an active high driver. Conversely, if a given strap input is resistively pulled high, then the corresponding output is configured as an active low driver.
Refer to Figure 31 for an example of strap connections to external components. In this example, the strapping results in Mode 1 for LED_0 and Mode 2 for LED_1.
The adaptive nature of the LED outputs helps to simplify potential implementation issues of these dual purpose pins.
The following conditions must be accounted when using LEDs: