参数资料
型号: MC68HC912BL16FU8
厂商: FREESCALE SEMICONDUCTOR INC
元件分类: 微控制器/微处理器
英文描述: 16-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP64
封装: QFP-64
文件页数: 82/128页
文件大小: 3326K
代理商: MC68HC912BL16FU8
MC68HC912BL16TS/D
57
9.5.3 Interrupts
PSEL is initialized in the HPRIO register with the value $F2, causing the external IRQ pin to have the
highest I-bit interrupt priority. The IRQ pin is configured for level-sensitive operation (for wired-OR sys-
tems). However, the interrupt mask bits in the CPU12 CCR are set to mask X and I related interrupt
requests.
9.5.4 Parallel I/O
If the MCU comes out of reset in an expanded mode, port A and port B are used for the multiplexed
address/data bus and port E pins are normally used to control the external bus (operation of port E pins
can be affected by the PEAR register). If the MCU comes out of reset in a single-chip mode, all ports
are configured as general-purpose high-impedance inputs. Port S, port T, port P, and port AD are all
configured as general-purpose inputs.
9.5.5 Central Processing Unit
After reset, the CPU fetches a vector from the appropriate address, then begins executing instructions.
The stack pointer and other CPU registers are indeterminate immediately after reset. The CCR X and
I interrupt mask bits are set to mask any interrupt requests. The S bit is also set to inhibit the STOP
instruction.
9.5.6 Memory
After reset, the internal register block is located at $0000–$01FF, the register-following space is at
$0200–$03FF, and RAM is at $0800–$09FF. EEPROM is located at $0E00–$0FFF. Flash EEPROM is
located at $C000–$FFFF in single-chip modes and at $4000–$7FFF (but disabled) in expanded modes.
9.5.7 Other Resources
The timer, serial communications interface (SCI), serial peripheral interface (SPI), pulse-width modula-
tor (PWM), and analog-to-digital converter (ATD) are off after reset.
9.6 Register Stacking
Once enabled, an interrupt request can be recognized at any time after the I bit in the CCR is cleared.
When an interrupt service request is recognized, the CPU responds at the completion of the instruction
being executed. Interrupt latency varies according to the number of cycles required to complete the in-
struction. Some of the longer instructions can be interrupted and will resume normally after servicing
the interrupt.
When the CPU begins to service an interrupt, the instruction queue is cleared, the return address is cal-
culated, and then it and the contents of the CPU registers are stacked as shown in Table 18.
After the CCR is stacked, the I bit (and the X bit, if an XIRQ interrupt service request is pending) is set
to prevent other interrupts from disrupting the interrupt service routine. The interrupt vector for the high-
est priority source that was pending at the beginning of the interrupt sequence is fetched, and execution
continues at the referenced location. At the end of the interrupt service routine, an RTI instruction re-
stores the content of all registers from information on the stack, and normal program execution re-
sumes. If another interrupt is pending at the end of an interrupt service routine, the register unstacking
and restacking is bypassed and the vector of the pending interrupt is fetched.
Table 18 Stacking Order on Entry to Interrupts
Memory Location
CPU Registers
SP – 2
RTNH : RTNL
SP – 4
YH : YL
SP – 6
XH : XL
SP – 8
B : A
SP – 9
CCR
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
..
.
相关PDF资料
PDF描述
MC68HC912BL16VFU8 16-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP64
MK74CG117AFT 90 MHz, OTHER CLOCK GENERATOR, PDSO48
MC68HC08AS32ACFU 8-BIT, MROM, 8.4 MHz, MICROCONTROLLER, PQFP64
MC68HRC98JL3ECFA 8-BIT, FLASH, 4 MHz, MICROCONTROLLER, PQFP48
MC68HRC98JL3EMDW 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDSO28
相关代理商/技术参数
参数描述
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
MC68HC916P1VAA16 功能描述:IC MCU 32K FLASH 16MHZ 80-QFP RoHS:是 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:HC16 标准包装:1 系列:AVR® ATmega 核心处理器:AVR 芯体尺寸:8-位 速度:16MHz 连通性:I²C,SPI,UART/USART 外围设备:欠压检测/复位,POR,PWM,WDT 输入/输出数:32 程序存储器容量:32KB(16K x 16) 程序存储器类型:闪存 EEPROM 大小:1K x 8 RAM 容量:2K x 8 电压 - 电源 (Vcc/Vdd):2.7 V ~ 5.5 V 数据转换器:A/D 8x10b 振荡器型:内部 工作温度:-40°C ~ 125°C 封装/外壳:44-TQFP 包装:剪切带 (CT) 其它名称:ATMEGA324P-B15AZCT
MC68HC916P3CFU16 制造商:Rochester Electronics LLC 功能描述:16BIT MCU FOR GENERAL - Bulk
MC68HC98LJ12CFU 制造商:Rochester Electronics LLC 功能描述: 制造商:Freescale Semiconductor 功能描述: