Nokia Customer Care
TF4 Technical Information
Company Confidential
TFE-4/RV-1
Issue 2.0 Mar/2005
Copyright
©
2005
Nokia Corporation.
Page 8b-31
Company Confidential
reset to the UPP. The BSI signal is used to load the value into the compare register. In
order to avoid spurious loading of the register, the BSI signal will be gated during UEM
"master-reset", and during "power-on" when PURX is active. The BSI signal should not
change state during normal operation unless the battery is extracted, in this case the BSI
signal will be pulled high, note a falling edge is required to load the compare register.
MBus
The default data transmission speed of MBus is 9.6 kbit/s. during flash programming,
UEM’s digital section generates a "Flash mode" signal. This will set-up the MBus line so
that it only can be used for input, and the clock signal from the prommer can be con-
nected. When the FPS8 prommer box is connected to the MBus, the transmission speed
is increased up to 6.5 Mbit/s. The data speed can be changed by the SW algorithm inside
the box, but the maximum speed is 6.5 Mbit/s.
FBUS
FBUS is an asynchronous data bus having separate TX and RX signals. Default bit rate of
the bus is 115.2 Kbit/s. FBUS is mainly used for controlling the phone in the production
and for interface to PC via DLR-3 or DAU-9P. Secondly, it can be used for flashing pur-
pose after the production phase.
MCU Boot.
When the MCU boots, it looks for flash programming indication by reading the status on
the MBUS signal. If this signal is pulled low the MCU sets up the UART in synchronous
mode, and indicates to the flash prommer, by setting FBUS_TX low, that it is ready to
accept the secondary boot-code. All flash programming related SW that is downloaded is
done so to the UPP internal MCU SRAM. The MCU also ends up in "flash programming
mode", if the contents of the flash is empty (reading FFH from the first memory location
in the flash).
Table 6: MBus interface
Signal
Parameter
Min
Typ
Max
Unit
Mbus
V
IH
1.95
2.78
3.0
Volt
V
IL
0
0.2
0.83
V
OH
1.95
2.78
2.83
V
OL
0
0.2
0.83
Table 7: FBUS interface
Signal
Parameter
Min
Typ
Max
Unit
FBUS_RX
V
IH
1.95
2.78
3.0
Volt
V
IL
0
0.2
0.83
FBUS_TX
V
OH
1.95
2.78
2.83
V
OL
0
0.2
0.83
