SNLS504G October 2015 – June 2026 DP83867CS , DP83867E , DP83867IS
PRODUCTION DATA
The DP83867 supports four configurable Light Emitting Diode (LED) pins: LED_0, LED_1, and LED_2. Configure a GPIO pin to operate as LED_3. Multiplex several functions onto the LEDs for different modes of operation. Select the LED operation mode using the LEDCR1 register (address 0x0018).
Because the LED output pins are also used as straps, consider the external components required for strapping and LED usage to avoid contention. Specifically, when using the LED outputs to directly drive LEDs, the active state of each output driver depends 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. In the context of the 4-level straps, this occurs for modes 1, 2, and 3. Conversely, if a given strap input is resistively pulled high, then the corresponding output is configured as an active low driver. In the context of the 4-level straps, this occurs only for mode 4.
See also Figure 7-12 for an example of strap connections to external components. In this example, the strapping results in Mode 1 for LED_0 and Mode 4 for LED_1.
The adaptive nature of the LED outputs helps to simplify potential implementation issues of these dual purpose pins.
Figure 7-12 Example Strap Connections