EM9304 interrupt pin

On the Apollo2 Blue MCU, the EM9304 interrupt pin (gpio46) is normally an input, and will not draw any current.

But if the EM9304 is powered off, the BLE controller's interrupt pin runs in an unknown state. The EM9304 interrupt pin is just floating, and will switch uncontrolled between high and low level logic, and cause current leakage.

It is recommended to pull the pin to ground on the BLE chip side, or just disable the pin in software:

    am_bsp_pin_disable(EM9304_INT);

Unterminated in hardware or not disabled in software, the pin could cause about 5 uA’s leakage current.

 1.Before disabling EM9304 interrupt pin

2. After disabling EM9304 interrupt pin