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CCS Technical Documentation
Baseband Power Up
The baseband power is controller by the flash prommer in production and in reprogram-
ming situations. Applying supply voltage to the battery terminals, the baseband will
power up. Once the baseband is powered, flash-programming indication is done as
described in the following section.
Flash Programming Indication
Flash programming is indicated to the UPP using MBUSRX signal between UPP and UEM.
The MBUS signal from the baseband to the flash prommer is used as clock for the syn-
chronous communication. The flash prommer keeps the MBUS line low during UPP boot
to indicate that the flash prommer is connected. If the UPP MBUSRX signal is low on
UPP, the MCU enters flash programming mode. In order to avoid accidental entry to the
flash-programming mode, the MCU only waits for a specified time to get input data from
the flash prommer. If the timer expires without any data being received, the MCU will
continue the boot sequence. The MBUS signal from UEM to the external connection is
used as clock during flash programming. This means that flash-programming clock is
supplied to UPP on the MBUSRX signal.
The flash prommer indicates the UEM that flash programming/reprogramming by writing
an 8-bit password to the UEM. The data is transmitted on the FBUSRX line and the UEM
clocks the data on the FBUSRX line into a shift register. When the 8 bits have been
shifted in the register, the flash prommer generates a falling edge on the BSI line. This
loads the shift register content in the UEM into a compare register. If the 8 bits in the
compare registers match with the default value preset in the UEM. The flash prommer
pulls the MBUS signal to UEM low in order to indicate to the MCU that the flash prom-
mer is connected. The UEM reset state machine performs a reset to the system, PURX low
for 20 ms. The UEM flash programming mode is valid until MCU sets a bit in the UEM
register that indicates the end of flash programming. Setting this bit also clears the com-
pare register in the UEM previously loaded at the falling edge of the BSI signal. During
the flash programming mode, the UEM watchdogs are disabled. Setting the bit indicating
end of flash programming enables and resets the UEM watchdog timer to its default
value. Clearing the flash programming bit also causes the UEM to generate a reset to the
UPP.
The BSI signal is used to load the value into the compare register. In order to avoid spuri-
ous loading of the register, the BSI signal will be gated during UEM master reset and dur-
ing 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.
Flashing
•
Flash programming is done by using FBUSTX, FBUSRX, MBUS, and
BSI lines.
•
When phone is connected to the prommer, the prommer will first set BSI
to "1" and then uses FBUSRX for writing and MBUS for clocking. The
prommer will indicate to UEM that flash programming will take place by
writing 8-bit password (*0xC9") to UEM after BSI is set to high. After the
Issue 1 04/2003
Nokia Corporation
Troubleshooting — BB
Confidential
RH-44
Page 7
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Troubleshooting
