User Guide

RM-11

System Module CC Technical Documentation

•EMC strategy

• Test interface

UEM and UPP

The UEM contains a series of voltage regulators to supply both the baseband module and

the RF module. Both the RF and baseband modules are supplied with regulated voltages

of 2.78 V and 1.8 V. The UEM contains six linear LDO (low drop-out) regulators for the

baseband and seven regulators for RF circuitry. The RF regulator VR1 uses two LDOs and

a charge pump. The VR1 regulator is used by the RF module. The core of the UPP is sup-

plied with a programmable voltage of 1.0 V, 1.3 V, 1.5 V, or 1.8 V. Note that with the

UEMK, VCORE supply voltage is set to 1.5 V.

The UPP operates from a 19.2 MHz clock generated in the RF ASIC. The DSP and MCU

both contain phase locked loop (PLL) clock multipliers, which can multiply the system

frequency by factors from 0.25 to 31. The actual execution speed is limited by the

memory configuration and process size (Max. DSP speed for C035 is ~ 200MHz).

The UEM contains a real-time clock, sliced down from the 32768 Hz crystal oscillator.

The UPP uses the 32768 Hz clock as the sleep clock.

The communication between the UEM and the UPP is done via the bi-directional serial

busses, CBUS and DBUS. The CBUS is controlled by the MCU and operates at a speed of

1.08 MHz. The DBUS is controlled by the DSP and operates at a speed of 9.6 MHz. Both

processors are located in the UPP.

The interface between baseband and RF is implemented in the UEM and UPP ASIC. The

UEM provides A/D and D/A conversion of the in-phase and quadrature receive and trans-

mit signal paths. It also provides A/D and D/A conversions of received and transmitted

audio signals to and from the user interface. The UEM supplies the analog signals to the

RF section according to the UPP DSP digital control. The RF ASIC is controlled via the UPP

RFBUS serial interface. There are also separate signals for PDM-coded audio. Digital

speech processing is handled by the DSP inside the UPP ASIC. The UEM is a dual voltage

circuit with the digital parts running from the baseband supply (1.8 V) and the analog

parts running from the analog supply of 2.78 V. The input battery voltage (VBAT) is also

used directly by some UEM blocks.

The baseband supports both internal and external microphone inputs as well as speaker

outputs. Input and output signal source selection and gain control are done by the UEM

according to control messages from the UPP. Keypad tones, DTMF, and other audio tones

are generated and encoded by the UPP and transmitted to the UEM for decoding. The

RM-11 has two external serial control interfaces: FBUS and MBUS provided by the UEM.

These busses can be accessed only through production test patterns. RM-11 also uses the

UPP8MV3 and UEMK.