Datasheet

Between these two successive transmissions, no pause is inserted; the SS pin remains
low.
The following figure shows the clock formats when CPHA = 0. At the top of the figure,
the eight bit times are shown for reference with bit 1 starting as the slave is selected (SS
IN goes low), and bit 8 ends at the last SPSCK edge. The MSB first and LSB first lines
show the order of SPI data bits depending on the setting in LSBFE. Both variations of
SPSCK polarity are shown, but only one of these waveforms applies for a specific
transfer, depending on the value in CPOL. The SAMPLE IN waveform applies to the
MOSI input of a slave or the MISO input of a master. The MOSI waveform applies to the
MOSI output pin from a master and the MISO waveform applies to the MISO output
from a slave. The SS OUT waveform applies to the slave select output from a master
(provided MODFEN and SSOE = 1). The master SS output goes to active low at the start
of the first bit time of the transfer and goes back high one-half SPSCK cycle after the end
of the eighth bit time of the transfer. The SS IN waveform applies to the slave select input
of a slave.
SS OUT
SS IN
(SLAVE)
(MASTER)
(SLAVE OUT)
MISO
MSB FIRST
LSB FIRST
MOSI
(MASTER OUT)
(MISO OR MOSI)
SAMPLE IN
SPSCK
(CPOL = 1)
SPSCK
(CPOL = 0)
BIT TIME #
(REFERENCE)
BIT 7
BIT 0
BIT 6
BIT 1
BIT 2
BIT 5
BIT 0
BIT 7
BIT 1
BIT 6
1
2
6
7
8
...
...
...
Figure 16-16. SPI Clock Formats (CPHA = 0)
Functional Description
MC9S08PA60 Reference Manual, Rev. 1, 9/2012
442 Freescale Semiconductor, Inc.