ST72F561K9TA STMicroelectronics, ST72F561K9TA Datasheet - Page 117

• Manufacturer Part Number: ST72F561K9TA
• Description: IC MCU 8BIT 60K FLASH 32-LQFP
• Manufacturer: STMicroelectronics
• Series: ST7r

Specifications of ST72F561K9TA

• Core Processor: ST7
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: CAN, LINSCI, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 24
• Program Memory Size: 60KB (60K x 8)
• Program Memory Type: FLASH
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 3.8 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-LQFP
• For Use With: 497-8374 - BOARD DEVELOPMENT FOR ST72F561
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

SERIAL PERIPHERAL INTERFACE (cont’d)
10.6.5.4
Configurations
There are two types of SPI systems:
– Single Master System
– Multimaster System
Single Master System
A typical single master system may be configured
using a device as the master and four devices as
slaves (see
The master device selects the individual slave de-
vices by using four pins of a parallel port to control
the four SS pins of the slave devices.
The SS pins are pulled high during reset since the
master device ports will be forced to be inputs at
that time, thus disabling the slave devices.
Note: To prevent a bus conflict on the MISO line,
the master allows only one active slave device
during a transmission.
Figure 76. Single Master / Multiple Slave Configuration
5V
Single
Figure
MOSI
SS
SCK
SCK
MOSI
Master
Device
Device
Slave
76).
Master
MISO
MISO
SS
and
Multimaster
MOSI
SCK
Device
Slave
MISO
SS
For more security, the slave device may respond
to the master with the received data byte. Then the
master will receive the previous byte back from the
slave device if all MISO and MOSI pins are con-
nected and the slave has not written to its SPIDR
register.
Other transmission security methods can use
ports for handshake lines or data bytes with com-
mand fields.
Multimaster System
A multimaster system may also be configured by
the user. Transfer of master control could be im-
plemented using a handshake method through the
I/O ports or by an exchange of code messages
through the serial peripheral interface system.
The multimaster system is principally handled by
the MSTR bit in the SPICR register and the MODF
bit in the SPICSR register.
MOSI
SCK
Device
Slave
MISO
SS
MOSI
SCK
Device
Slave
MISO
SS
ST72561
117/265