TDA5235
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, the global states, and is generally
responsible for automating data reception, verification, identification, extraction, and
storage into the FIFO. The payload data without RUNIN, TSI and optional EOM can be
read from the FIFO via SPI by the external microcontroller.
Alternatively, a transparent data stream can also 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 TDA5235 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, as well as between Run and SLEEP
Mode must be initiated by the microcontroller.
In Self Polling Mode, TDA5235 autonomously polls for incoming RF signals. The
receiver switches automatically between up to two configurations (Configuration A and
B). 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. If the following received data matches to the TSI pattern, and passes the
optional message ID screening, the payload is loaded into the FIFO, and, if not masked,
an interrupt is generated. Then the payload data can be read via SPI.
Data Sheet
95
V1.0, 2010-02-19
INFINEON [ Infineon ]
