Rainbow Electronics ATmega64M1 - Manual (Page 160)

160
8209A–AVR–08/09
ATmega16M1/32M1/64M1
Figure 19-3. SPI Transfer Format with CPHA = 0
Figure 19-4. SPI Transfer Format with CPHA = 1
19.5 Register Description
19.5.1 MCUCR – MCU Control Register
Bit 7– SPIPS: SPI Pin Redirection
Thanks to SPIPS (SPI Pin Select) in MCUCR Sfr, SPI pins can be redirected.
• When the SPIPS bit is written to zero, the SPI signals are directed on pins MISO,MOSI, SCK
and SS.
• When the SPIPS bit is written to one,the SPI signals are directed on alternate SPI pins,
MISO_A, MOSI_A, SCK_A and SS_A.
Note that programming port are always located on alternate SPI port.
Bit 1
Bit 6 LSB
MSB
SCK (CPOL = 0)
mode 0
SAMPLE I
MOSI/MISO
CHANGE 0
MOSI PIN
CHANGE 0
MISO PIN
SCK (CPOL = 1)
mode 2
SS
MSB
LSB Bit 6
Bit 1 Bit 5
Bit 2 Bit 4
Bit 3 Bit 3
Bit 4 Bit 2
Bit 5 MSB first (DORD = 0)
LSB first (DORD = 1)
SCK (CPOL = 0)
mode 1
SAMPLE I
MOSI/MISO
CHANGE 0
MOSI PIN
CHANGE 0
MISO PIN
SCK (CPOL = 1)
mode 3
SS
MSB
LSB Bit 6
Bit 1 Bit 5
Bit 2 Bit 4
Bit 3 Bit 3
Bit 4 Bit 2
Bit 5 Bit 1
Bit 6 LSB
MSB MSB first (DORD = 0)
LSB first (DORD = 1)
Bit 7 6 5 4 3 2 1 0
SPIPS – – PUD – – IVSEL IVCE MCUCR
Read/Write R/W R R R/W R R R/W R/W
Initial Value 0 0 0 0 0 0 0 0