User Guide

CCS Technical Documentation 2 - System Module
RH-26
Issue 1 02/04 ©Nokia Corporation Page 37
Figure 19: Flip PWB construction
Security
The phone flash program and IMEI codes are software protected using an external secu-
rity device that is connected between the phone and a PC.
After sales interface
Test pads are placed on the engine PWB for service troubleshooting purposes. The same
test pattern is used for after sales purposes as well.
In the pin assignment below, pins numbered 1, 4, and 5 are not in use.
Figure 20: Pin assignment in standard 5-pin production test pattern, PWB view.
FBUS interface
FBUS is an asynchronous data bus having separate TX and RX signals. Default bit rate of
the bus is 115.2 kbit/s. FBUS can also be accessed via system connector.
MBUS Interface
MBUS interface is used for controlling the phone in R&D and AS. It is a bi-directional
serial bus between the phone and PC. The phone initialization is made using MBUS. The
default transmission speed is 9.6 kbit/s.
STI_CLK (1)
VPP (6)
STI_TX (8kHz sync clock for DAI)
STI_RX (5)
NC (9)
MBUS
(
7
)
GND (8)
FBUS_RX (3)
FBUS_TX (2)
(4)