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M0A21/M0A23 Series
May 06, 2022
Page
530
of 746
Rev 1.02
M0
A21
/M
0
A
2
3
SE
RIES
TEC
H
NICAL
RE
FEREN
C
E
M
ANUAL
Supports Word Suspend function
Supports PDMA transfer
Supports 3-wire, no slave select signal, bi-direction interface
Supports wake-up function by slave select signal in Slave mode
Supports one data channel half-duplex transfer
6.14.3 Block Diagram
Peripheral
Device
User
Interface
Control Register
Data
Buffer
Data
Shift
Unit
SPI Protocol
Processor
Unit
Input
Processor
Buffer
Control
Interrupt
Generation
USCIx_DAT0/1
To Interrupt
Signal
USCIx_CLK
USCIx_CTL0
Wake-up
Control
Protocol-Relative
Clock Generator
f
PCLK
Output
Configuration
Note:
x = 0, 1
Figure 6.14-3 USCI SPI Mode Block Diagram
6.14.4 Basic Configuration
USCI0 SPI Basic Configurations
Clock Source Configuration
–
Enable USCI0 peripheral clock in USCI0CKEN (CLK_APBCLK1[8]).
–
Enable USCI0_SPI function on USCI0 USPI_CTL[2:0] register,
USPI_CTL[2:0]=3
’b001
Reset Configuration
–
Reset USCI0 controller in USCI0RST (SYS_IPRST2[8]).
Pin Configuration
Group
Pin Name
GPIO
MFP
USCI0
USCI0_CLK
PA.0~PA.5, PB.4~PB.7, PC.0~PC.7
MFP10
PD.4
MFP4