参数资料
型号: MC68HC908RK2DW
厂商: FREESCALE SEMICONDUCTOR INC
元件分类: 微控制器/微处理器
英文描述: 8-BIT, FLASH, 4 MHz, MICROCONTROLLER, PDSO20
封装: PLASTIC, SOIC-20
文件页数: 145/158页
文件大小: 1020K
代理商: MC68HC908RK2DW
Functional Description
MC68HC908RK2 Data Sheet, Rev. 5.1
Freescale Semiconductor
87
7.3.2 IRQ Pin
A logic 0 on the IRQ pin can latch an interrupt request into the IRQ latch. A vector fetch, software clear,
or reset clears the IRQ latch. If the MODEI bit is set, the IRQ pin is both falling-edge sensitive and
low-level sensitive. With MODEI set, both of these actions must occur to clear the IRQ latch:
Vector fetch or software clear — A vector fetch generates an interrupt acknowledge signal to clear
the latch. Software may generate the interrupt acknowledge signal by writing a 1 to the ACKI bit in
the IRQ and keyboard status and control register (INTKBSCR). The ACKI bit is useful in
applications that poll the IRQ pin and require software to clear the IRQ latch. Writing to the ACKI
bit can also prevent spurious interrupts due to noise. Setting ACKI does not affect subsequent
transitions on the IRQ pin. A falling edge on IRQ that occurs after writing to the ACKI bit latches
another interrupt request. If the IRQ mask bit, IMASKI, is clear, the CPU loads the program counter
with the vector address at locations $FFFA and $FFFB.
Return of the IRQ pin to logic 1 — As long as the IRQ pin is at logic 0, the IRQ latch remains set.
The vector fetch or software clear and the return of the IRQ pin to logic 1 can occur in any order. The
interrupt request remains pending as long as the IRQ pin is at logic 0. A reset will clear the latch and the
MODEI control bit, thereby clearing the interrupt even if the pin stays low.
If the MODEI bit is clear, the IRQ pin is falling-edge sensitive only. With MODEI clear, a vector fetch or
software clear immediately clears the IRQ latch.The IRQF bit in the INTKBSCR register can be used to
check for pending interrupts. The IRQF bit is not affected by the IMASKI bit, which makes it useful in
applications where polling is preferred.
Use the BIH or BIL instruction to read the logic level on the IRQ pin.
NOTE
When using the level-sensitive interrupt trigger, avoid false interrupts by
masking interrupt requests in the interrupt routine.
7.3.3 KBI Module During Break Interrupts
The system integration module (SIM) controls whether the IRQ or keyboard interrupt latchs can be
cleared during the break state. The BCFE bit in the break flag control register (BFCR) enables software
to clear the latches during the break state. See 10.7.3 SIM Break Flag Control Register.
To allow software to clear the IRQ or keyboard latchs during a break interrupt, write a 1 to the BCFE bit.
If a latch is cleared during the break state, it remains cleared when the MCU exits the break state.
To protect the latch during the break state, write a 0 to the BCFE bit. With BCFE at 0 (its default state),
writing to the ACKI or ACKK bits in the IRQ and keyboard status and control register during the break
state has no effect on the IRQ or keyboard latchs.
7.3.4 Keyboard Interrupt Pins
Writing to the KBIE6–KBIE1 bits in the keyboard interrupt enable register independently enables or
disables each port A pin as a keyboard interrupt pin. Enabling a keyboard interrupt pin also enables its
internal pullup device. A logic 0 applied to an enabled keyboard interrupt pin latches an IRQ/keyboard
interrupt request.
相关PDF资料
PDF描述
MC68HC912BL16CFU8 16-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP64
MC68HC916X1CTH16 16-BIT, FLASH, 16.78 MHz, MICROCONTROLLER, PQFP120
MC916X1CTH16B1 16-BIT, FLASH, 16.78 MHz, MICROCONTROLLER, PQFP120
SPMC916X1CTH16 16-BIT, FLASH, 16.78 MHz, MICROCONTROLLER, PQFP120
MC68HCL05J1ADWR2 8-BIT, MROM, 2.1 MHz, MICROCONTROLLER, PDSO20
相关代理商/技术参数
参数描述
MC68HC908SR12CB 功能描述:IC MCU 12K FLASH 8MHZ 42-SDIP RoHS:否 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:HC08 标准包装:250 系列:56F8xxx 核心处理器:56800E 芯体尺寸:16-位 速度:60MHz 连通性:CAN,SCI,SPI 外围设备:POR,PWM,温度传感器,WDT 输入/输出数:21 程序存储器容量:40KB(20K x 16) 程序存储器类型:闪存 EEPROM 大小:- RAM 容量:6K x 16 电压 - 电源 (Vcc/Vdd):2.25 V ~ 3.6 V 数据转换器:A/D 6x12b 振荡器型:内部 工作温度:-40°C ~ 125°C 封装/外壳:48-LQFP 包装:托盘 配用:MC56F8323EVME-ND - BOARD EVALUATION MC56F8323
MC68HC908SR12CFA 功能描述:MICROCONTROLLER 48 PIN RoHS:否 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:HC08 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
MC68HC912B32CFU8 功能描述:IC MCU 32K FLASH 8MHZ 80-QFP RoHS:否 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:HC12 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
MC68HC916P1CAA16 功能描述:16位微控制器 - MCU 16B MCU 32K FLASH RoHS:否 制造商:Texas Instruments 核心:RISC 处理器系列:MSP430FR572x 数据总线宽度:16 bit 最大时钟频率:24 MHz 程序存储器大小:8 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:VQFN-40 安装风格:SMD/SMT
MC68HC916P1CFU16 制造商:Rochester Electronics LLC 功能描述:16BIT W/32KB FLASH EEPRO - Bulk