參數(shù)資料
型號: MC68HLC908QY2CDT
廠商: FREESCALE SEMICONDUCTOR INC
元件分類: 微控制器/微處理器
英文描述: 8-BIT, FLASH, 2 MHz, MICROCONTROLLER, PDSO16
封裝: TSSOP-16
文件頁數(shù): 177/186頁
文件大?。?/td> 2765K
代理商: MC68HLC908QY2CDT
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁第117頁第118頁第119頁第120頁第121頁第122頁第123頁第124頁第125頁第126頁第127頁第128頁第129頁第130頁第131頁第132頁第133頁第134頁第135頁第136頁第137頁第138頁第139頁第140頁第141頁第142頁第143頁第144頁第145頁第146頁第147頁第148頁第149頁第150頁第151頁第152頁第153頁第154頁第155頁第156頁第157頁第158頁第159頁第160頁第161頁第162頁第163頁第164頁第165頁第166頁第167頁第168頁第169頁第170頁第171頁第172頁第173頁第174頁第175頁第176頁當(dāng)前第177頁第178頁第179頁第180頁第181頁第182頁第183頁第184頁第185頁第186頁
Low-Voltage Inhibit (LVI)
Data Sheet
MC68HLC908QY/QT Family — Rev. 2
90
Low-Voltage Inhibit (LVI)
MOTOROLA
The LVI is enabled out of reset. The LVI module contains a bandgap reference
circuit and comparator. Clearing the LVI power disable bit (LVIPWRD) enables the
LVI to monitor VDD voltage. Clearing the LVI reset disable bit (LVIRSTD) enables
the LVI module to generate a reset when VDD falls below a voltage, VTRIPF or
VDTRIPF. Setting the LVI enable in stop mode bit (LVISTOP) enables the LVI to
operate in stop mode. Setting the LVD or LVR trip point bit (LVDLVR) selects the
LVD trip point voltage. The actual trip thresholds are specified in 16.5 DC
Electrical Characteristics. Either trip level can be used as a detect or reset.
NOTE:
After a power-on reset, the LVI’s default mode of operation is LVR trip voltage. If a
higher trip voltage is desired, the user must set the LVDLVR bit to raise the trip
point to the LVD voltage.
If the user requires the higher trip voltage and sets the LVDLVR bit after power-on
reset while the VDD supply is not above the VTRIPR for LVD mode, the
microcontroller unit (MCU) will immediately go into reset. The next time the LVI
releases the reset, the supply will be above the VTRIPR for LVD mode.
Once an LVI reset occurs, the MCU remains in reset until VDD rises above a
voltage, VTRIPR, which causes the MCU to exit reset. See Section 13. System
Integration Module (SIM) for the reset recovery sequence.
The output of the comparator controls the state of the LVIOUT flag in the LVI status
register (LVISR) and can be used for polling LVI operation when the LVI reset is
disabled.
10.3.1 Polled LVI Operation
In applications that can operate at VDD levels below the VTRIPF level, software can
monitor VDD by polling the LVIOUT bit. In the configuration register, the LVIPWRD
bit must be cleared to enable the LVI module, and the LVIRSTD bit must be set to
disable LVI resets.
10.3.2 Forced Reset Operation
In applications that require VDD to remain above the VTRIPF level, enabling LVI
resets allows the LVI module to reset the MCU when VDD falls below the VTRIPF
level. In the configuration register, the LVIPWRD and LVIRSTD bits must be
cleared to enable the LVI module and to enable LVI resets.
10.3.3 Voltage Hysteresis Protection
Once the LVI has triggered (by having VDD fall below VTRIPF), the LVI will maintain
a reset condition until VDD rises above the rising trip point voltage, VTRIPR. This
prevents a condition in which the MCU is continually entering and exiting reset if
VDD is approximately equal to VTRIPF. VTRIPR is greater than VTRIPF by the
hysteresis voltage, VHYS.
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(guān)PDF資料
PDF描述
MC68HLC908QT1P 8-BIT, FLASH, 2 MHz, MICROCONTROLLER, PDIP8
MC68HLC908QT1CDW 8-BIT, FLASH, 2 MHz, MICROCONTROLLER, PDSO8
MC68HLC98JL3EIP 8-BIT, FLASH, 2 MHz, MICROCONTROLLER, PDIP28
MC68HC908KL3ECP 8-BIT, FLASH, 4 MHz, MICROCONTROLLER, PDIP28
MC68HC908JK3ECP 8-BIT, FLASH, 4 MHz, MICROCONTROLLER, PDIP20
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC68HLC908QY2CDW 制造商:Rochester Electronics LLC 功能描述:LOW V-1.5K FLASH W/ADC - Bulk
MC68HLC908QY2CP 制造商:Rochester Electronics LLC 功能描述:LOW V-1.5K FLASH W/ADC - Bulk
MC68HLC908QY2DW 制造商:Rochester Electronics LLC 功能描述:- Bulk
MC68HLC908QY4CDW 制造商:Rochester Electronics LLC 功能描述: 制造商:Freescale Semiconductor 功能描述:
MC68HLC908QY4CP 制造商:Rochester Electronics LLC 功能描述:LOW V-4K FLASH W/ADC - Bulk