TDA5225 Datasheet, PDF (57/176 Pages) Infineon Technologies AG – Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver

TDA5225
Functional Description
2.6
System Management Unit (SMU)
The System Management Unit consists of two main units:
• Master Control Unit, where the various operating modes can be configured.
• Polling Timer Unit, where the receiver’s On and Off times and modes are defined.
The Polling Timer Unit is only working in the Self Polling Mode.
2.6.1 Master Control Unit (MCU)
2.6.1.1 Overview
The Master Control Unit controls the operation modes and the global states.
The transparent data stream can be processed externally by the Application Controller
(see Chapter 2.5.1.2 Data Interface).
The following operation modes and the behavior of the Master Control Unit are fully
automatic and only influenced by SFR settings and by incoming RF data streams.
The TDA5225 has two major operation modes, which are switched by SFR bit MSEL.
In Slave Mode the device is controlled via SPI by the external microcontroller. This mode
supports:
• Run Mode Slave (RMS), where the receiver is continuously active
• SLEEP Mode, where the receiver is switched off for power saving. This mode can
also be used to change register settings
• HOLD Mode, allows register settings to be changed. The change to HOLD Mode and
back to RMS is faster than changing to SLEEP Mode and back to RMS.
In Slave Mode, switching between configurations and channels, as well as between Run
and SLEEP Mode must be initiated by the microcontroller.
In Self Polling Mode, TDA5225 autonomously polls for incoming RF signals. The
receiver switches automatically between up to four configurations (Configuration A, B, C
and D) and up to 3 channels per configuration (Further information can be found in
Chapter 2.6.2).
Between the RF signal scans, the receiver is automatically switched to Low Power Mode
for reducing the average power consumption. If an incoming signal fulfills the selected
wake-up criterion an interrupt can be generated and Run Mode Self Polling will be
entered.
Data Sheet
57
V1.0, 2010-02-19