C8051F960-B-GM Datasheet, PDF (425/492 Pages) Silicon Laboratories – Ultra Low Power 128K, LCD MCU Family

C8051F96x
31. Enhanced Serial Peripheral Interface with DMA Support (SPI1)
The Enhanced Serial Peripheral Interface (SPI1) provides access to a flexible, full-duplex synchronous
serial bus. SPI1 can operate as a master or slave device in both 3-wire or 4-wire modes, and supports
multiple masters and slaves on a single SPI bus. The slave-select (NSS) signal can be configured as an
input to select SPI1 in slave mode, or to disable Master Mode operation in a multi-master environment,
avoiding contention on the SPI bus when more than one master attempts simultaneous data transfers.
NSS can also be configured as a chip-select output in master mode, or disabled for 3-wire operation.
Additional general purpose port I/O pins can be used to select multiple slave devices in master mode.
SFR Bus
SPI0CKR
SPI0CFG
SPI0CN
SYSCLK
Clock Divide
Logic
SPI CONTROL LOGIC
Data Path
Control
Pin Interface
Control
SPI IRQ
Tx Data
MOSI
C
SPI0DAT
Transmit Data Buffer
SCK ^R
O
Shift Register
76543210
Pin
S
Control
Logic
Rx Data
MISO
S
B
A
R
Receive Data Buffer
NSS
Write
SPI0DAT
Read
SPI0DAT
SFR Bus
Figure 31.1. SPI Block Diagram
Port I/O
Rev. 1.0
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