MMC2001
INTERVAL MODE SERIAL PERIPHERAL INTERFACE
MOTOROLA
REFERENCE MANUAL
12-7
PHA — Phase
This bit controls the phase shift of the SPI_CLK. (See Figure 12-2)
0 =
Normal phase
1 =
Shift advance to opposite phase
POL — Polarity
This bit controls the polarity of the SPI_CLK. (See Figure 12-2)
0 =
Normal polarity
1 =
Inverted polarity
SPIGP — SPI_GP Control
This bit controls the data on the SPI_GP pin.
0 =
Pin driven low
1 =
Pin driven high
BAUD RATE
These bits select the baud rate of the ISPI bit clock based on divisions of the system
clock. The master clock for the ISPI is HI_REFCLK.
CLOCK COUNT
These bits select the length of the transfer and control the justification of data. From
two to 16 bits can be transferred. A count of all zeros causes the ISPI to be disabled.
Table 12-2 BAUD RATE Field Settings
Value
Divide By
000
8
001
16
010
32
011
64
100
128
101
256
110
512
111
1024
Table 12-3 CLOCK COUNT Field Settings
Value
Meaning
0000
Disable ISPI
0001
2-bit transfer
.
.
.
.
0111
8-bit transfer
.
.
.
.
1111
16-bit transfer
Freescale Semiconductor,
I
Freescale Semiconductor, Inc.
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