User's Manual

Developers Kit
Preliminary 14
the radio be in API Serial Interface Mode to execute the Command Set or to configure any of the
EEPROM parameters.
To force the radio into API Serial Interface Mode 03, pin 27 must be held at logic
low level and the radio reset. The radio can not be placed into any of the Transparent Serial Interface
Modes 01, 02 or 04 until pin 27 is held at logic high level and reset.
4.3.7 Microprocessor Reset (uP RESET)
Microprocessor Reset (uP RESET) is achieved by holding pin 38 at logic high level for a
minimum of 2ms. If uP RESET is performed after power has been applied to the radio and is stable, the
reset time will be significantly less. At all other times, pin 38 should be logic low level. If pin 38 is not
connected, the microprocessor will hold pin 38 at logic low level.
4.3.8 EEPROM Write Protect (E2WP)
EEPROM Write Protect (EEWP) is enabled when pin 37 is at logic high level or left floating. Pin
37 must be logic low level to Write to the EEPROM.