1） ANTout and ANTin are to be connected with pi-matching network. Connected line is recommended to be as short as possible. *2） Connection is necessary for writing program to the OTP via UART. Other GPIO pin can be used for VPP_CONTROL instead of P0_7. Please see the document “Hardware setup Guide for OTP Programming”。 Other pairs of GPIO can be used for UART instead of P0_4 and P0_5. Please see the document “Overview of DA1458X Initial Boot Sequence and Available Interface Pins”。 *3） Connection is necessary for software debugging in your product via J-Link. OTP writing can also be done using J-Link. Please see the document “Hardware Setup for Software Debugging”。 RST input logic should be inverted externally if J-Link reset is enabled. *4） 10 GPIOs （P0_0 to P0_7， P1_0 and P1_1） are available for multipurpose use. P0_0 to P0_3 can be used for analog input. Note： XTAL32K_DISABLE_AMPREG register should be ‘1’ for using external OSC. See DA14580 datasheet for more details. Note： Internal RCX oscillator might be functional for sleep clock instead of external 32kHz XTAL / OSC under some limitations noted below： - Environment temperature change is flat， connection interval 《 2sec. - Confirmation in actual condition should be done enough by the customer’s responsibility.