CCS Technical Documentation
Troubleshooting - Baseband
RH-34
Issue 1 11/2003 Confidential
©
2003
Nokia Corporation
Page 15
Flash Programming
Connections to Baseband
The Flash programming equipment is connected to the baseband using test pads for gal-
vanic connection. The test pads are allocated in such a way that they can be accessed
when the phone is assembled. The flash programming interface consist of the VPP,
FBUSTX, FBUSRX, MBUS, and BSI signals and use by the FPS8 to flash. The connection is
through the UEM which means that the logic voltage levels are corresponding to 2.78V.
Power is supplied to the phone using the battery contacts.
Baseband Power Up
The baseband power is controller by the flash prommer in production and in re-program-
ming situations. Applying supply voltage to the battery terminals will cause the base-
band to 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 matches with the default value preset in the UEM, programming
starts. At this point the flash prommer shall pull the MBUS signal to UEM low in order to
indicate to the MCU that the flash prommer 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 program-
ming. Setting this bit also clears the compare register in the UEM previously loaded at
the falling edge of the BSI signal. During the flash programming mode the UEM watch-
dogs 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,
