Power Up and Reset

Power up and reset is controlled by the UEM ASIC. NHM-7 baseband can be powered up in following ways:

1. Press power button which means grounding the PWRONX pin of the UEM

2. Connect the charger to the charger input

3. Supply battery voltage to the battery pin

4. RTC Alarm, the RTC has been programmed to give an alarm

After receiving one of the above signals, the UEM counts a 20ms delay and then enters it's reset mode. The watchdog starts up, and if the battery voltage is greater than Vcoff+ a 200ms delay is started to allow references etc. to settle. After this delay elapses the VFLASH1 regulator is enabled. 500us later VR3, VANA, VIO and VCORE are enabled. Finally the PURX (Power Up Reset) line is held low for 20 ms. This reset, PURX, is fed to the baseband ASIC UPP, resets are generated for the MCU and

PAMS Technical Documentation the DSP. During this reset phase the UEM forces the VCTCXO regulator on regardless of the status of the sleep control input signal to the UEM. The FLSRSTx from the ASIC is used to reset the flash during power up and to put the flash in power down during sleep. All baseband regulators are switched on at the UEM power on except SIM and VFLASH2 regulators which are controlled by the MCU. The UEM internal watchdogs are running during the UEM reset state, with the longest watchdog time selected. If the watchdog expires the UEM returns to power off state. The UEM watchdogs are internally acknowledged at the rising edge of the PURX signal in order to always give the same watchdog response time to the MCU.

The UEM contains the following A/D converter channels that are used for several measurement purpose. The general slow A/D converter is a 10 bit converter using the the UEM interface clock for the conversion. An interrupt will be given at the end of the measurement.

The UEM's 11-channel analog to digital converter is used to monitor charging functions, battery functions, voltage levels in external accessory detection inputs, user interface and RF functions.

When the conversion is started the converter input is selected. Then the signal processing block creates a data with MSB set to '1' and and others to '0'. In the D/A converter this data controls the switches which connect the input reference voltage (VrefADC) to the resistor network. The generated output voltage is compared with the input voltage under measurement and if the latter is greater, MSB remains '1' else it is set '0'. The following step is to test the next bit and the next...until LSB is reached. The result is then stored to ADCR register for UPP to read.

The monitored battery functions are battery voltage (VBATADC), battery type (BSI) and battery temperature (BTEMP) indication.

The battery type is recognized through a resistive voltage divider. In phone there is a 100k0hm pull up resistor in the BSI line and the battery has a pull down resistor in the same line. Depending on the battery type the pull down resistor value is changed. The battery temperature is measured equivalently except that the battery has a NTC pull down resistor in the BTEMP line.

KEYB1&2 inputs are used for keyboard scanning purposes. These inputs are also routed internally to the miscellaneous block. In NHM-7 KEYB1 input is used for flip detection.

The HEADINT and HOOKINT are external accessory detection inputs used for monitoring voltage levels in these inputs. They are routed internally from the miscellaneous block and they are connected to the converter through a 2/1 multiplexer.

The monitored RF functions are PATEMP and VCXOTEMP detection. PA-TEMP input is used to measure temperature of the RFIC, Hagar. VCXOTEMP is not used in NHM-7.

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