SPI Protocol
SPI Operation Using the Clock Stop Mode
6-2
SPRU592E
6.1 SPI Protocol
The SPI protocol is a master-slave configuration with one master device and
one or more slave devices. The interface consists of the following four signals:
-
Serial data input (also referred to as Master In
−
Slave Out, or MISO)
-
Serial data output (also referred to as Master Out
−
Slave In, or MOSI)
-
Shift-clock (also referred to as SCK)
-
Slave-enable signal (also referred to as SS)
A typical SPI interface with a single slave device is shown in Figure 6
Figure 6
−
1. Typical SPI Interface
SPI-compliant
SCK
MOSI
MISO
SS
SPI-compliant
slave
SCK
MOSI
MISO
SS
master
The master device controls the flow of communication by providing shift-clock
and slave-enable signals. The slave-enable signal is an optional active-low
signal that enables the serial data input and output of the slave device (the
device not sending out the clock).
In the absence of a dedicated slave-enable signal, communication between
the master and slave is determined by the presence or absence of an active
shift-clock. When the McBSP is operating in SPI master mode and the SS
signal is not used by the slave SPI port, the slave device must remain enabled
at all times, and multiple slaves cannot be used.
Summary of Contents for TMS320VC5509
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Page 43: ...McBSP Operation 2 20 SPRU592E This page is intentionally left blank ...
Page 105: ...SPI Operation Using the Clock Stop Mode 6 16 SPRU592E This page is intentionally left blank ...
Page 187: ...Transmitter Configuration 8 40 SPRU592E This page is intentionally left blank ...
Page 191: ...General Purpose I O on the McBSP Pins 9 4 SPRU592E This page is intentionally left blank ...
Page 201: ...Emulation Power and Reset Considerations 10 10 SPRU592E ...
Page 207: ...Data Packing Examples 11 6 SPRU592E This page is intentionally left blank ...
Page 273: ...McBSP Register Worksheet 13 14 SPRU592E This page is intentionally left blank ...