ST72321AR6-Auto STMicroelectronics, ST72321AR6-Auto Datasheet - Page 122

• Manufacturer Part Number: ST72321AR6-Auto
• Description: 8-bit MCU for automotive with 32 Kbyte Flash, 10-bit ADC, timers, SPI, SCI and I2C interfaces
• Manufacturer: STMicroelectronics

Specifications of ST72321AR6-Auto

• Hdflash Endurance: 100 cycles, data retention 20 years
• Clock Sources: crystal/ceramic resonator oscillators, internal RC oscillator and bypass for external clock
• 4 Power Saving Modes: Halt, Active Halt, Wait and Slow

Serial peripheral interface (SPI)
Figure 55. Serial peripheral interface block diagram
14.3.1
122/243
MOSI
MISO
SCK
SS
Functional description
A basic example of interconnections between a single master and a single slave is
illustrated in
The MOSI pins are connected together and the MISO pins are connected together. In this
way data is transferred serially between master and slave (most significant bit first).
The communication is always initiated by the master. When the master device transmits
data to a slave device via MOSI pin, the slave device responds by sending data to the
master device via the MISO pin. This implies full duplex communication with both data out
and data in synchronized with the same clock signal (which is provided by the master device
via the SCK pin).
To use a single data line, the MISO and MOSI pins must be connected at each node (in this
case only simplex communication is possible).
Four possible data/clock timing relationships may be chosen (see
slave must be programmed with the same timing mode.
SOD
bit
SPIDR
Figure
8-bit Shift Register
Read Buffer
SERIAL CLOCK
56.
GENERATOR
CONTROL
MASTER
Data/Address Bus
Read
Write
Doc ID 13829 Rev 1
7
SPIF WCOL
SPIE
7
SPE
CONTROL
STATE
SPR2
OVR
SPI
Interrupt
request
MODF
MSTR
Figure
CPOL
0
CPHA
59) but master and
SOD
ST72321xx-Auto
SS
SPICSR
SPICR
SSM
SPR1
0
1
SPR0
SSI
0
0