15. Combination of USART, SPI, and I2C (USI)
A96G150 User's manual
192
Figure 88. USIn SPI Clock Formats when CPHAn = 1
When CPHAn = 1, the slave begins to drive its MISOn output when SSn goes active low, but the data
is not defined until the first SCKn edge. The first SCKn edge shifts the first bit of data from the shifter
onto the MOSIn output of the master and the MISOn output of the slave. The next SCKn edge causes
both the master and slave to sample the data bit value on their MISOn and MOSIn inputs, respectively.
At the third SCKn edge, the USIn shifts the second data bit value out to the MOSIn and MISOn output
of the master and slave respectively. When CPHAn=1, the
slave’s SSn input is not required to go to its
inactive high level between transfers.
Because the SPI logic reuses the USIn resources, SPI mode of operation is similar to that of
synchronous or asynchronous operation. An SPI transfer is initiated by checking for the USIn Data
Register Empty flag (DREn=1) and then writing a byte of data to the USInDR Register.
In master mode of operation, even if transmission is not enabled (TXEn=0), writing data to the USInDR
register is necessary because the clock SCKn is generated from transmitter block.
SCKn
(CPOLn=1)
MISOn
MOSIn
SCKn
(CPOLn=0)
/SSn OUT
(MASTER)
BIT7
BIT0
/SSn IN
(SLAVE)
BIT6
BIT1
…
…
BIT2
BIT5
BIT0
BIT7
BIT1
BIT6
SAMPLE
MSB First
LSB First
Содержание A96G150
Страница 126: ...12 Timer 0 1 2 3 4 5 A96G150 User s manual 126 Figure 43 16 bit Timer Counter Mode Operation Example...
Страница 136: ...12 Timer 0 1 2 3 4 5 A96G150 User s manual 136 Figure 51 16 bit Timer Counter Mode Operation Example...
Страница 147: ...A96G150 User s manual 12 Timer 0 1 2 3 4 5 147 Figure 59 16 bit Timer Counter Mode Operation Example...
Страница 157: ...A96G150 User s manual 12 Timer 0 1 2 3 4 5 157 Figure 67 16 bit Timer Counter Mode Operation Example...
Страница 171: ...A96G150 User s manual 14 12 bit ADC 171 Figure 79 ADC Operation Flow Sequence...
Страница 333: ...A96G150 User s manual Revision history 333 Revision history Revision Date Notes 1 00 2022 06 22 First creation...