eZ80L92 MCU
Product Specification
128
Serial Peripheral Interface
The Serial Peripheral Interface (SPI) is a synchronous interface allowing several SPI-type
devices to be interconnected. The SPI is a full-duplex, synchronous, and character-
oriented communication channel that employs a four-wire interface. The SPI block con-
sists of a transmitter, receiver, baud rate generator, and control unit. During an SPI trans-
fer, data is sent and received simultaneously by both the master and the slave SPI devices.
In a serial peripheral interface, separate signals are required for data and clock. The SPI
may be configured as either a master or a slave. The connection of two SPI devices (one
master and one slave) and the direction of data transfer is demonstrated in Figure 27 and
Figure 28.
MASTER
SS
MISO
Bit 0
Bit 7
DATAOUT
CLKOUT
DATAIN
SCK
8-Bit Shift Register
Baud Rate
Generator
Figure 27. SPI Master Device
SLAVE
SS
ENABLE
MOSI
SCK
Bit 0
Bit 7
MISO
DATAOUT
DATAIN
CLKIN
8-Bit Shift Register
Figure 28. SPI Slave Device
PS013015-0316
Serial Peripheral Interface
ZILOG [ ZILOG, INC. ]
