STV3550B STMicroelectronics, STV3550B Datasheet - Page 101

• Manufacturer Part Number: STV3550B
• Manufacturer: STMicroelectronics

Specifications of STV3550B

• Operating Temperature (min): 0C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Lead Free Status / Rohs Status: Compliant

STV3550
7.7.3
7.7.4
PIO pad connection and control
In I²C mode, only the SDA pad will be used as an input and output.
The SDA and SCL pads are provided by 2 bits of a standard ST20 PIO block. Their
directions (input, output or bidirectional) can therefore be configured in software using the
appropriate PIO settings. Consequently the SSC2 does not need to provide automatic
control of data pad directions and does not need to provide a bidirectional clock port.
The connections between the SSC2 ports and the relevant PIO pads are shown in
Figure
Figure 66. PIO pad connections to SSC2
The pad control block inside the SSC2 determines which of the serial_data_in ports is used
to read data from (depending on the master or slave mode). It also determines which of the
serial_data_out ports to write data to (depending on the master or slave mode).
The deselected serial_data_out port is driven to ground (except in I²C mode when it is
driven high). Therefore the user must ensure that the relevant PIO pad output enable is
turned off depending on the master/slave status of the SSC.
It is up to the user to ensure that the PIO pads are configured correctly for direction and
output driver type (e.g. push/pull or open drain).
Throughout the rest of this document the data in and out ports will be referred to as
“serial_data_out” and “serial_data_in”, where this is assumed to be the correct pair of pins
dependent on the master or slave mode of the SSC2.
Clock generation
If the SSC2 is configured to be the bus master, then it will generate a serial clock signal on
the serial_clock_out port.
The clock signal can be controlled for polarity and phase and its period (baud rate) can be
set to a variety of frequencies.
For I²C operation there are also a number of additional clocking features.
66.
serial_clock_out
serial_data_out
serial_clock_in
serial_data_in
alt_data_out<X>
alt_data_out<Y>
data_from_pads<Y>
data_from_pads<X>
output_enable<X>
output_enable<Y>
PIO
TV chassis control
SDA
SCL
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