NEX ROBOTICS Fire Bird V ATMEGA2560 Software Manual page 114

Bits 1, 0 – SPR1, SPR0: SPI Clock Rate Select 1 and 0
These two bits control the SCK rate of the device configured as a Master. SPR1 and SPR0 have
no effect on the Slave. The relationship between SCK and the Oscillator Clock frequency f
shown in the table 9.3.
Table 9.3: Relationship between SCK and the oscillator frequency
© NEX Robotics Pvt. Ltd. and ERTS Lab IIT Bombay, INDIA
SPI2X SPR1
0 0
0 0
0 1
0 1
1 0
1 0
1 1
1 1
Figure 9.4: SPI transfer format with CPHA = 0
Figure 9.5: SPI transfer format with CPHA = 1
Fire Bird V ATMEGA2560 Software Manual
SPR0 SCK Frequency
0 F /4
osc
1 F /16
osc
0 F /64
osc
1 F /128
osc
0 F /2
osc
1 F /8
osc
0 F /32
osc
1 F /64
osc
is
osc
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