参数资料
型号: MC68HC705F8B
厂商: FREESCALE SEMICONDUCTOR INC
元件分类: 微控制器/微处理器
英文描述: 8-BIT, OTPROM, 1.8 MHz, MICROCONTROLLER, PDIP56
封装: PLASTIC, SDIP-56
文件页数: 81/126页
文件大小: 1084K
代理商: MC68HC705F8B
MOTOROLA
6-10
MC68HC05F8
TIMERS
6
6.2
TIMER B - RELOADABLE TIMER
The Reloadable Timer is similar to the Free-running Timer, with the following differences:
The 16-bit timer counter is automatically reloaded from the preset timer registers upon
underow occurs.
There is no input capture function, i.e. no TCAP.
There is no output compare function, i.e. no TCMP.
The Reloadable Timer is convenient for generating periodic interrupts without the aid of software.
In addition, the timer counter value can be read in a similar way to timer A.
6.2.1
Functional Description
See Figure 6-6 for a block diagram of the Reloadable Timer.
The timer B is driven by a clock which is derived from E divided by 4, 8, 16 or 32. In the Control
Register, two bits TCSB0 and TCSB1 are used to select the divider for the prescaler, TBOIE is an
interrupt enable bit, TMEB is a Timer B enable bit which will inhibit the driving clock when it is clear.
Upon reset, the Control Register is cleared, Timer B is disabled, Timer B interrupt is inhibited, the
free running counter and the Preset Register are all congured to $FFFF.
The preset register should be written with proper value before enable the Timer B. A low to high
transition of the TMBE bit loads the timer counter with the content in the preset register and
activates the driving clock, then the free running counter starts to count down, when it rolls over
from $0001 to $0000 an interrupt is generated with timer B underow ag set if the TBOIE is set,
meanwhile a “load” signal is produced to reload the counter with the content of the preset register,
thus interruption will occur periodically.
6.2.2
Resolution and Maximum Period
When a 3.579MHz crystal is used, the timer resolution and its maximum period are shown in
Table 6-2 Reloadable Timer Resolution and Maximum Period
TCSB1
TCSB0
FREQUENCY
RESOLUTION
MAX. PERIOD PRESET $FFFF
0
E/4
2.25
s
147ms
0
1
E/8
4.5
s
294ms
1
0
E/16
9
s
588ms
1
E/32
18
s
1176ms
Where E = internal bus clock
TPG
56
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
..
.
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
In
c
..
.
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
相关PDF资料
PDF描述
MC68HC705SJ7CDW 8-BIT, OTPROM, 2.1 MHz, MICROCONTROLLER, PDSO20
MC68HC908JK3EMDW 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDSO20
MC68HC05C9AB 8-BIT, MROM, 2.1 MHz, MICROCONTROLLER, PDIP42
MC68HC705KJ1C 8-BIT, OTPROM, 4 MHz, MICROCONTROLLER, PDIP16
MC68HC908LK24CPB 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP64
相关代理商/技术参数
参数描述
MC68HC705G1B 制造商:Rochester Electronics LLC 功能描述:- Bulk
MC68HC705J1A 制造商:Freescale Semiconductor 功能描述:
MC68HC705J1ACDW 功能描述:IC MCU 4MHZ 1.2K OTP 20-SOIC RoHS:否 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:HC05 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
MC68HC705J1ACP 功能描述:IC MCU 4MHZ 1.2K OTP 20-DIP RoHS:否 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:HC05 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
MC68HC705J1ACPE 功能描述:8位微控制器 -MCU HCO5 CORE+1.2K RAM + EPR 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