Nokia 8390 Manuales De Servicio
NSB-8
System Module & UI
PAMS Technical Documentation
Page 22
ãNokia Corporation
Issue 1 01/02
A/D Channels
The UEM contains the following A/D converter channels that are used for several mea-
surement purpose. The general slow A/D converter is a 10 bit converter using the UEM
interface clock for the conversion. An interrupt will be given at the end of the measure-
ment.
surement purpose. The general slow A/D converter is a 10 bit converter using the UEM
interface clock for the conversion. An interrupt will be given at the end of the measure-
ment.
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.
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 process-
ing block creates a data with MSB set to '1' 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.
ing block creates a data with MSB set to '1' 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.
battery temperature (BTEMP) indication.
The battery type is recognized through a resistive voltage divider. In phone there is a
100kOhm 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 but the battery has a NTC pull down resis-
tor in the BTEMP line.
100kOhm 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 but the battery has a NTC pull down resis-
tor in the BTEMP line.
KEYB1&2 inputs are used for keyboard scanning purposes. These inputs are also routed
internally to the miscellaneous block.
internally to the miscellaneous block.
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.
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. PATEMP input is used
for measuring temperature of the RFIC, Hagar. VCXOTEMP is not used in NSB-8.
for measuring temperature of the RFIC, Hagar. VCXOTEMP is not used in NSB-8.
IR Module
The IR interface, when using 2.7 V transceiver, is designed into the UEM. The IR link sup-
ports speeds from 9600 bit/s to 1.152 MBit/s up to distance of 1 m. Transmission over
the IR if half-duplex.
ports speeds from 9600 bit/s to 1.152 MBit/s up to distance of 1 m. Transmission over
the IR if half-duplex.
The length of the transmitted IR pulse depends on the speed of the transmission. When
230.4 kbit/s or less is used as a transmission speed, pulse length maximum is 1.63 us. If
transmission speed is set to 1.152 Mbit/s the pulse length is 154 ns according to IrDA
specification.
230.4 kbit/s or less is used as a transmission speed, pulse length maximum is 1.63 us. If
transmission speed is set to 1.152 Mbit/s the pulse length is 154 ns according to IrDA
specification.