参数资料
型号: AT89LP428-20AU
厂商: Atmel
文件页数: 143/149页
文件大小: 0K
描述: MCU 8051 4K FLASH SPI 32TQFP
产品培训模块: MCU Product Line Introduction
标准包装: 250
系列: 89LP
核心处理器: 8051
芯体尺寸: 8-位
速度: 20MHz
连通性: SPI,UART/USART
外围设备: 欠压检测/复位,POR,PWM,WDT
输入/输出数: 30
程序存储器容量: 4KB(4K x 8)
程序存储器类型: 闪存
EEPROM 大小: 512 x 8
RAM 容量: 768 x 8
电压 - 电源 (Vcc/Vdd): 2.4 V ~ 5.5 V
振荡器型: 内部
工作温度: -40°C ~ 85°C
封装/外壳: 32-TQFP
包装: 托盘
93
3654A–MICRO–8/09
AT89LP428/828
Figure 17-2. SPI Master-Slave Interconnection
When the SPI is configured as a Master (MSTR in SPCR is set), the operation of the SS pin
depends on the setting of the Slave Select Ignore bit, SSIG. If SSIG = 1, the SS pin is a general-
purpose output pin which does not affect the SPI system. Typically, the pin will be driving the SS
pin of an SPI Slave. If SSIG = 1, SS must be held high to ensure Master SPI operation. If the SS
pin is driven low by peripheral circuitry when the SPI is configured as a Master with SSIG = 1,
the SPI system interprets this as another master selecting the SPI as a slave and starting to
send data to it. To avoid bus contention, the SPI system takes the following actions:
1.
The MSTR bit in SPCR is cleared and the SPI system becomes a Slave. As a result of
the SPI becoming a Slave, the MOSI and SCK pins become inputs.
2.
The MODF Flag in SPSR is set, and if the SPI interrupt is enabled, the interrupt routine
will be executed.
Thus, when interrupt-driven SPI transmission is used in Master mode, and there exists a possi-
bility that SS may be driven low, the interrupt should always check that the MSTR bit is still set. If
the MSTR bit has been cleared by a slave select, it must be set by the user to re-enable SPI
Master mode.
17.1
Master Operation
An SPI master device initiates all data transfers on the SPI bus. The AT89LP428/828 is config-
ured for master operation by setting MSTR = 1 in SPCR. Writing to the SPI data register (SPDR)
while in master mode loads the transmit buffer. If the SPI shift register is empty, the byte in the
transmit buffer is moved to the shift register; the transmit buffer empty flag, TXE, is set; and a
transmission begins. The transfer may start after an initial delay, while the clock generator waits
for the next full bit slot of the specified baud rate. The master shifts the data out serially on the
MOSI line while providing the serial shift clock on SCK. When the transfer finishes, the SPIF flag
is set to “1” and an interrupt request is generated, if enabled. The data received from the
addressed SPI slave device is also transferred from the shift register to the receive buffer.
Therefore, the SPIF bit flags both the transmit-complete and receive-data-ready conditions. The
received data is accessed by reading SPDR.
8-Bit Shift Register
Master
Slave
MSB
LSB
MSB
LSB
8-Bit Shift Register
MISO
DISSO
SSIG
MOSI
SS
GPIO
SSIG
VCC
SCK
MODF
Clock
Generator
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相关代理商/技术参数
参数描述
AT89LP428-20JU 功能描述:8位微控制器 -MCU SingleCycle 8051 4K ISP Flash 2.4V 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
AT89LP428-20MH 功能描述:8位微控制器 -MCU SingleCycle 8051 4K ISP Flash 2.4V 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
AT89LP428-20PU 功能描述:8位微控制器 -MCU SingleCycle 8051 4K ISP Flash 2.4V 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
AT89LP51-20AU 功能描述:8位微控制器 -MCU Single Cycle 8051 4K ISP FL 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
AT89LP51-20JU 功能描述:8位微控制器 -MCU Single Cycle 8051 4K ISP FL 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