ATMEGA8-16AI SL383 Atmel, ATMEGA8-16AI SL383 Datasheet - Page 132

• Manufacturer Part Number: ATMEGA8-16AI SL383
• Description: Semiconductors and Actives, Microprocessors, Microcontrollers
• Manufacturer: Atmel

Data Modes
132
ATmega8(L)
There are four combinations of SCK phase and polarity with respect to serial data, which are
determined by control bits CPHA and CPOL. The SPI data transfer formats are shown in
59
ensuring sufficient time for data signals to stabilize. This is clearly seen by summarizing
48
Table 51. CPOL and CPHA Functionality
Figure 59. SPI Transfer Format with CPHA = 0
Figure 60. SPI Transfer Format with CPHA = 1
and
and
CPOL = 0, CPHA = 0
CPOL = 0, CPHA = 1
CPOL = 1, CPHA = 0
CPOL = 1, CPHA = 1
MSB first (DORD = 0)
LSB first (DORD = 1)
Table
Figure
SCK (CPOL = 0)
mode 0
SCK (CPOL = 1)
mode 2
SAMPLE I
MOSI/MISO
CHANGE 0
MOSI PIN
CHANGE 0
MISO PIN
SCK (CPOL = 0)
mode 1
SCK (CPOL = 1)
mode 3
SAMPLE I
MOSI/MISO
CHANGE 0
MOSI PIN
CHANGE 0
MISO PIN
SS
SS
MSB first (DORD = 0)
LSB first (DORD = 1)
49, as done below:
60. Data bits are shifted out and latched in on opposite edges of the SCK signal,
MSB
LSB
Sample (Falling)
MSB
LSB
Sample (Rising)
Leading Edge
Setup (Falling)
Setup (Rising)
Bit 6
Bit 1
Bit 6
Bit 1
Bit 5
Bit 2
Bit 5
Bit 2
Bit 4
Bit 3
Sample (Falling)
Sample (Rising)
Bit 4
Bit 3
Setup (Falling)
Trailing Edge
Setup (Rising)
Bit 3
Bit 4
Bit 3
Bit 4
Bit 2
Bit 5
Bit 2
Bit 5
Bit 1
Bit 6
SPI Mode
Bit 1
Bit 6
0
1
2
3
LSB
MSB
2486W–AVR–02/10
LSB
MSB
Figure
Table