CBUS interface
CBUS is a main system control bus in BB5. RAPIDO controls the functionality of EM ASICs AVilma (N2200) and
Betty (N2300) with CBUS.
CBUS is a four-wire half-duplex master-slave interface. In HW52 CBUS clock frequency is 4.39 MHz.
FBUS interface
FBUS is a 2-wire serial communication bus between HW52 engine and service SW.
ECI interface
The ECI (Enhancement Control Interface) is a point-to-point, bi-directional, single line serial bus.
The purpose of the ECI is to identify and authenticate the accessory, and to act as a data bus (intended for
control purposes) between the phone and the accessory .
USB charger interface
The main battery can be charged from the USB port. Default charging current level is 80 – 100 mA during the
initial charging. Primary charging current level is up to 500 mA from USB Host and up to 1.25A from USB wall
charger with external switch-mode USB Charger BQ24150.
Page 8 –20
Figure 68 HS USB block diagram
COMPANY CONFIDENTIAL
Copyright © 2009 Nokia. All rights reserved.
RM-505; RM-506
System Module and User Interface
Issue 1