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NUC126
Aug. 08, 2018
Page
789
of 943
Rev 1.03
NUC12
6 S
E
RI
E
S
T
E
CH
NI
CA
L R
E
F
E
RE
NCE
MA
NUA
L
SPI_CLK
SPI_MOSI
SPI_MISO
TX0[6]
TX0[0]
TX1[7]
TX1[6]
LSB
TX1[0]
RX0[6]
RX0[0]
RX1[6]
LSB
RX1[0]
MSB
RX0[7]
RX1[7]
MSB
TX0[7]
SPI_SS
SCLKMODE=0x0
SCLKMODE=0x2
Slave Mode: FUNMODE=0x1, SLAVE=1, SLV3WIRE=0,
LSB=0, DWIDTH=0x8
CTLOINV=0
CTLOINV=1
Figure 6.21-18 SPI Timing in Slave Mode
SPI_CLK
SPI_MOSI
SPI_MISO
TX0[1]
TX0[7]
TX1[0]
TX1[1]
MSB
TX1[7]
RX0[1]
RX0[7]
RX1[1]
MSB
RX1[7]
LSB
RX0[0]
RX1[0]
LSB
TX0[0]
SPI_SS
SCLKMODE=0x1
SCLKMODE=0x3
Slave Mode: FUNMODE=0x1, SLAVE=1, SLV3WIRE=0,
LSB=1, DWIDTH=0x8
CTLOINV=0
CTLOINV=1
Figure 6.21-19 SPI Timing in Slave Mode (Alternate Phase of Serial Bus Clock)
6.21.5.12 Programming Flow
This section describes the programming flow for USCI SPI data transfer.
For Master mode,
1. Enable USCI peripheral clock by setting CLK_APBCLK1 register.
2. Configure user-specified pins as USCI function pins by setting corresponding multiple function
control registers.
3. Set FUNMODE (USPI_CTL[2:0]) to 1 to select SPI mode.