参数资料
型号: ST72C254G1M6
厂商: STMICROELECTRONICS
元件分类: 微控制器/微处理器
英文描述: 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDSO28
封装: 0.300 INCH, PLASTIC, SOIC-28
文件页数: 100/136页
文件大小: 929K
代理商: ST72C254G1M6
ST72104G, ST72215G, ST72216G, ST72254G
66/136
SERIAL PERIPHERAL INTERFACE (Cont’d)
12.3.4.7 Single Master and Multimaster 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 an MCU as the master and four MCUs as
slaves (see Figure 42).
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.
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 its DR regis-
ter.
Other transmission security methods can use
ports for handshake lines or data bytes with com-
mand fields.
Multi-master System
A multi-master 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 multi-master system is principally handled by
the MSTR bit in the CR register and the MODF bit
in the SR register.
Figure 42. Single Master Configuration
MISO
MOSI
MISO
SS
SCK
5V
Ports
Slave
MCU
Slave
MCU
Slave
MCU
Slave
MCU
Master
MCU
相关PDF资料
PDF描述
ST72C254G2M3 8-BIT, FLASH, 6 MHz, MICROCONTROLLER, PDSO28
ST72C254G2M7 8-BIT, FLASH, 6 MHz, MICROCONTROLLER, PDSO28
ST72C254G2M1 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDSO28
ST72C254G1B1 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDIP32
ST72C254G1B7 8-BIT, FLASH, 6 MHz, MICROCONTROLLER, PDIP32
相关代理商/技术参数
参数描述
ST72C254G2B1 制造商:STMicroelectronics 功能描述:8-BIT MICROCONTROLLER - Bulk
ST72C254G2B6 功能描述:8位微控制器 -MCU Flash 8K SPI/I2C RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72C254G2B6 制造商:STMicroelectronics 功能描述:8BIT MCU FLASH 8K 72C254 DIP32
ST72C254G2M3 功能描述:8位微控制器 -MCU ST72104G ST72215G ST72254G 8B MCU RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72C254G2M3/TR 功能描述:8位微控制器 -MCU 8B MCU SINGLE VLTG FLASH MEMORY RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT