參數(shù)資料
型號: MC68HC705JB2DW
廠商: FREESCALE SEMICONDUCTOR INC
元件分類: 微控制器/微處理器
英文描述: 8-BIT, OTPROM, 3 MHz, MICROCONTROLLER, PDSO20
封裝: SOIC-20
文件頁數(shù): 87/128頁
文件大?。?/td> 2493K
代理商: MC68HC705JB2DW
August 28, 1998
GENERAL RELEASE SPECIFICATION
PROGRAMMABLE TIMER
REV 1.1
9-3
The timer registers (TMRH, TMRL) shown in Figure 9-3 are read-only locations
which contain the current high and low bytes of the 16-bit free-running counter.
Writing to the timer registers has no effect. Reset of the device presets the timer
counter to $FFFC.
The TMRL latch is a transparent read of the LSB until the a read of the TMRH
takes place. A read of the TMRH latches the LSB into the TMRL location until the
TMRL is again read. The latched value remains xed even if multiple reads of the
TMRH take place before the next read of the TMRL. Therefore, when reading the
MSB of the timer at TMRH the LSB of the timer at TMRL must also be read to
complete the read sequence.
During power-on-reset (POR), the counter is initialized to $FFFC and begins
counting after the oscillator start-up delay. Because the counter is sixteen bits and
preceded by a xed divide-by-four prescaler, the value in the counter repeats
every 262, 144 internal bus clock cycles (524, 288 oscillator cycles).
When the free-running counter rolls over from $FFFF to $0000, the timer overow
ag bit (TOF) is set in the TSR. When the TOF is set, it can generate an interrupt if
the timer overow interrupt enable bit (TOIE) is also set in the TCR. The TOF ag
bit can only be reset by reading the TMRL after reading the TSR.
Other than clearing any possible TOF ags, reading the TMRH and TMRL in any
order or any number of times does not have any effect on the 16-bit free-running
counter.
NOTE
To prevent interrupts from occurring between readings of the TMRH
and TMRL, set the I bit in the condition code register (CCR) before
reading TMRH and clear the I bit after reading TMRL.
9.2
ALTERNATE COUNTER REGISTERS (ACRH, ACRL)
The functional block diagram of the 16-bit free-running timer counter and alternate
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
TMRH
R
TMRH7
TMRH6
TMRH5
TMRH4
TMRH3
TMRH2
TMRH1
TMRH0
$0018
W
reset:
11111111
TMRL
R
TMRL7
TMRL6
TMRL5
TMRL4
TMRL3
TMRL2
TMRL1
TMRL0
$0019
W
reset:
11111100
Figure 9-3. Programmable Timer Counter Registers (TMRH, TMRL)
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
..
.
相關PDF資料
PDF描述
MC68HC705JB2P 8-BIT, OTPROM, 3 MHz, MICROCONTROLLER, PDIP20
MC68HC705JB4P 8-BIT, OTPROM, 3 MHz, MICROCONTROLLER, PDIP28
MC68HC705K1CDW 8-BIT, OTPROM, 2 MHz, MICROCONTROLLER, PDSO16
MC68HC705K1CP 8-BIT, OTPROM, 2 MHz, MICROCONTROLLER, PDIP16
MC68HC705K1S 8-BIT, OTPROM, 2 MHz, MICROCONTROLLER, CDIP16
相關代理商/技術參數(shù)
參數(shù)描述
MC68HC705JB4DW 制造商:Motorola Inc 功能描述: 制造商:MOTOROLA 功能描述:
MC68HC705JJ7CDW 功能描述:IC MCU 8BIT 20-SOIC RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:HC05 其它有關文件:STM32F101T8 View All Specifications 特色產(chǎn)品:STM32 32-bit Cortex MCUs 標準包裝:490 系列:STM32 F1 核心處理器:ARM? Cortex?-M3 芯體尺寸:32-位 速度:36MHz 連通性:I²C,IrDA,LIN,SPI,UART/USART 外圍設備:DMA,PDR,POR,PVD,PWM,溫度傳感器,WDT 輸入/輸出數(shù):26 程序存儲器容量:64KB(64K x 8) 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:10K x 8 電壓 - 電源 (Vcc/Vdd):2 V ~ 3.6 V 數(shù)據(jù)轉換器:A/D 10x12b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 85°C 封裝/外殼:36-VFQFN,36-VFQFPN 包裝:托盤 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... 其它名稱:497-9032STM32F101T8U6-ND
MC68HC705JP7CDW 功能描述:IC MCU 8BIT 28-SOIC RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:HC05 其它有關文件:STM32F101T8 View All Specifications 特色產(chǎn)品:STM32 32-bit Cortex MCUs 標準包裝:490 系列:STM32 F1 核心處理器:ARM? Cortex?-M3 芯體尺寸:32-位 速度:36MHz 連通性:I²C,IrDA,LIN,SPI,UART/USART 外圍設備:DMA,PDR,POR,PVD,PWM,溫度傳感器,WDT 輸入/輸出數(shù):26 程序存儲器容量:64KB(64K x 8) 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:10K x 8 電壓 - 電源 (Vcc/Vdd):2 V ~ 3.6 V 數(shù)據(jù)轉換器:A/D 10x12b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 85°C 封裝/外殼:36-VFQFN,36-VFQFPN 包裝:托盤 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... 其它名稱:497-9032STM32F101T8U6-ND
MC68HC705JP7CP 制造商:Rochester Electronics LLC 功能描述: 制造商:Freescale Semiconductor 功能描述:
MC68HC705K1CDW 制造商:Motorola Inc 功能描述: