SPICLK (mode0)
Sampling
t
Lead
SPICLK (mode1)
SPICLK (mode2)
SPICLK (mode3)
Functional Description
24.3.1.3.6 Polarity and Phase
McSPI supports four sub-modes of the SPI format transfer that depend on the polarity (POL) and the
phase (PHA) of the SPI serial clock (SPICLK).
and
show a summary of the four
sub-modes. Software selects one of four combinations of serial clock phase and polarity.
Two consecutive SPI words for two different slave devices may go along with active SPICLK signal with
different phase and polarity.
Table 24-5. Phase and Polarity Combinations
Polarity (POL)
Phase (PHA)
SPI Mode
Comments
0
0
mode0
SPICLK active high and sampling occurs on the rising edge.
0
1
mode1
SPICLK active high and sampling occurs on the falling edge.
1
0
mode2
SPICLK active low and sampling occurs on the falling edge.
1
1
mode3
SPICLK active low and sampling occurs on the rising edge.
Figure 24-6. Phase and Polarity Combinations
4001
SPRUH73H – October 2011 – Revised April 2013
Multichannel Serial Port Interface (McSPI)
Copyright © 2011–2013, Texas Instruments Incorporated