User Guide

6015/6015i/6016i/6019i (RH-55), 6012 (RM-20)

Troubleshooting - Baseband Nokia Customer Care

input data from the flash prommer. If the timer expires without any data being received,

the MCU continues the boot sequence. The MBUS signal from the UEM to the external

connection is used as a clock during flash programming. This means that the flash

programming clock is supplied to the UPP on the MBUSRX signal.

The flash prommer indicates flash programming/reprogramming to the UEM 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. Programming starts if

the 8-bits in the compare register match with the default value preset in the UEM. At

this point the flash prommer pulls 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

the MCU sets a bit in the UEM register that indicates the end of flash programming.

Setting this bit also clears the compare register in the UEM, which was loaded at the

falling edge of the BSI signal. The UEM watchdogs are disabled during the flash

programming mode. Setting the bit indicating the 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

spurious loading of the register, the BSI signal is gated during the UEM master reset and

during power on when PURX is active. The BSI signal should not change states during

normal operation unless the battery is extracted. In this case the BSI signal will be pulled

high. Note that a falling edge is required to load the compare register.

Flashing

Flash programming is done through the VPP, FBUSTX, FBUSRX, MBUS, and BSI signals.

When the phone enters flash programming mode, the prommer indicates to the UEM

that flash programming will take place by writing an 8-bit password to the UEM. A

prommer first sets the BSI to "1", uses FBUSRX for writing, and uses the MBUS for

clocking. The BSI is then set back to "0".

The MCU uses the FBUSTX signal to indicate to the prommer that it has been noticed.

Then the MCU reports the UPP type ID and is ready to receive the secondary boot code in

its internal SRAM.