参数资料
型号: MC68HC711D3CFN2
厂商: FREESCALE SEMICONDUCTOR INC
元件分类: 微控制器/微处理器
英文描述: 8-BIT, OTPROM, 2 MHz, MICROCONTROLLER, PQCC44
封装: PLASTIC, LCC-44
文件页数: 112/138页
文件大小: 1047K
代理商: MC68HC711D3CFN2
Status Flags and Interrupts
MC68HC711D3 Data Sheet, Rev. 2.1
Freescale Semiconductor
75
6.8 Status Flags and Interrupts
The SCI transmitter has two status flags. These status flags can be read by software (polled) to tell when
the corresponding condition exists. Alternatively, a local interrupt enable bit can be set to enable each of
these status conditions to generate interrupt requests when the corresponding condition is present.
Status flags are automatically set by hardware logic conditions, but must be cleared by software, which
provides an interlock mechanism that enables logic to know when software has noticed the status
indication. The software clearing sequence for these flags is automatic — functions that are normally
performed in response to the status flags also satisfy the conditions of the clearing sequence.
TDRE and TC flags are normally set when the transmitter is first enabled (TE set to 1). The TDRE flag
indicates there is room in the transmit queue to store another data character in the TDR. The TIE bit is
the local interrupt mask for TDRE. When TIE is 0, TDRE must be polled. When TIE and TDRE are 1, an
interrupt is requested.
The TC flag indicates the transmitter has completed the queue. The TCIE bit is the local interrupt mask
for TC. When TCIE is 0, TC must be polled; when TCIE is 1 and TC is 1, an interrupt is requested.
Writing a 0 to TE requests that the transmitter stop when it can. The transmitter completes any
transmission in progress before actually shutting down. Only an MCU reset can cause the transmitter to
stop and shut down immediately. If TE is written to 0 when the transmitter is already idle, the pin reverts
to its general-purpose I/O function (synchronized to the bit-rate clock). If anything is being transmitted
when TE is written to 0, that character is completed before the pin reverts to general-purpose I/O, but any
other characters waiting in the transmit queue are lost. The TC and TDRE flags are set at the completion
of this last character, even though TE has been disabled.
The SCI receiver has five status flags, three of which can generate interrupt requests. The status flags
are set by the SCI logic in response to specific conditions in the receiver. These flags can be read (polled)
at any time by software. Refer to Figure 6-9, which shows SCI interrupt arbitration.
When an overrun takes place, the new character is lost, and the character that was in its way in the
parallel RDR is undisturbed. RDRF is set when a character has been received and transferred into the
parallel RDR. The OR flag is set instead of RDRF if overrun occurs. A new character is ready to be
transferred into RDR before a previous character is read from RDR.
The NF and FE flags provide additional information about the character in the RDR, but do not generate
interrupt requests.
The last receiver status flag and interrupt source come from the IDLE flag. The RxD line is idle if it has
constantly been at logic 1 for a full character time. The IDLE flag is set only after the RxD line has been
busy and becomes idle, which prevents repeated interrupts for the whole time RxD remains idle.
相关PDF资料
PDF描述
MC68HLC908QT4CP 8-BIT, FLASH, 2 MHz, MICROCONTROLLER, PDIP8
MCF5233CVM100 32-BIT, 100 MHz, RISC PROCESSOR, PBGA256
MC908GR60AVFJ 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP32
MC68HRC98JL3ECP 8-BIT, FLASH, 4 MHz, MICROCONTROLLER, PDIP28
MC68HC05C4ACP 8-BIT, MROM, 2.1 MHz, MICROCONTROLLER, PDIP40
相关代理商/技术参数
参数描述
MC68HC711D3CFNE2 功能描述:8位微控制器 -MCU 8B OTP 192RAM 2 MHZ 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
MC68HC711D3CFNE3 功能描述:8位微控制器 -MCU 8B OTP 192RAM 2 MHZ 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
MC68HC711D3VFNE2 功能描述:8位微控制器 -MCU 8B OTP 192RAM 2 MHZ 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
MC68HC711E20CFN2 功能描述:IC MCU 20K 2MHZ OTP 52-PLCC RoHS:否 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:HC11 其它有关文件:STM32F101T8 View All Specifications 特色产品:STM32 32-bit Cortex MCUs 标准包装:490 系列:STM32 F1 核心处理器:ARM? Cortex?-M3 芯体尺寸:32-位 速度:36MHz 连通性:I²C,IrDA,LIN,SPI,UART/USART 外围设备:DMA,PDR,POR,PVD,PWM,温度传感器,WDT 输入/输出数:26 程序存储器容量:64KB(64K x 8) 程序存储器类型:闪存 EEPROM 大小:- RAM 容量:10K x 8 电压 - 电源 (Vcc/Vdd):2 V ~ 3.6 V 数据转换器:A/D 10x12b 振荡器型:内部 工作温度:-40°C ~ 85°C 封装/外壳:36-VFQFN,36-VFQFPN 包装:托盘 配用:497-10030-ND - STARTER KIT FOR STM32497-8853-ND - BOARD DEMO STM32 UNIV USB-UUSCIKSDKSTM32-PL-ND - KIT IAR KICKSTART STM32 CORTEXM3497-8512-ND - KIT STARTER FOR STM32F10XE MCU497-8505-ND - KIT STARTER FOR STM32F10XE MCU497-8304-ND - KIT STM32 MOTOR DRIVER BLDC497-6438-ND - BOARD EVALUTION FOR STM32 512K497-6289-ND - KIT PERFORMANCE STICK FOR STM32MCBSTM32UME-ND - BOARD EVAL MCBSTM32 + ULINK-MEMCBSTM32U-ND - BOARD EVAL MCBSTM32 + ULINK2更多... 其它名称:497-9032STM32F101T8U6-ND
MC68HC711E20CFN3 功能描述:IC MCU 3MHZ 20K OTP 52-PLCC RoHS:否 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:HC11 其它有关文件:STM32F101T8 View All Specifications 特色产品:STM32 32-bit Cortex MCUs 标准包装:490 系列:STM32 F1 核心处理器:ARM? Cortex?-M3 芯体尺寸:32-位 速度:36MHz 连通性:I²C,IrDA,LIN,SPI,UART/USART 外围设备:DMA,PDR,POR,PVD,PWM,温度传感器,WDT 输入/输出数:26 程序存储器容量:64KB(64K x 8) 程序存储器类型:闪存 EEPROM 大小:- RAM 容量:10K x 8 电压 - 电源 (Vcc/Vdd):2 V ~ 3.6 V 数据转换器:A/D 10x12b 振荡器型:内部 工作温度:-40°C ~ 85°C 封装/外壳:36-VFQFN,36-VFQFPN 包装:托盘 配用:497-10030-ND - STARTER KIT FOR STM32497-8853-ND - BOARD DEMO STM32 UNIV USB-UUSCIKSDKSTM32-PL-ND - KIT IAR KICKSTART STM32 CORTEXM3497-8512-ND - KIT STARTER FOR STM32F10XE MCU497-8505-ND - KIT STARTER FOR STM32F10XE MCU497-8304-ND - KIT STM32 MOTOR DRIVER BLDC497-6438-ND - BOARD EVALUTION FOR STM32 512K497-6289-ND - KIT PERFORMANCE STICK FOR STM32MCBSTM32UME-ND - BOARD EVAL MCBSTM32 + ULINK-MEMCBSTM32U-ND - BOARD EVAL MCBSTM32 + ULINK2更多... 其它名称:497-9032STM32F101T8U6-ND