- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄359141 > MC68HC08KH12A (飛思卡爾半導(dǎo)體(中國)有限公司) Microcontrollers PDF資料下載
參數(shù)資料
| 型號： | MC68HC08KH12A |
| 廠商： | 飛思卡爾半導(dǎo)體(中國)有限公司 |
| 英文描述： | Microcontrollers |
| 中文描述： | 微控制器 |
| 文件頁數(shù)： | 65/178頁 |
| 文件大小： | 925K |
| 代理商： | MC68HC08KH12A |
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頁當(dāng)前第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頁第177頁第178頁
Functional Description
MC68HC08KH12A Data Sheet, Rev. 1.1
Freescale Semiconductor
65
8.3.1 Crystal Oscillator Circuit
The crystal oscillator circuit consists of an inverting amplifier and an external crystal. The OSC1 pin is the
input to the amplifier and the OSC2 pin is the output. The SIMOSCEN signal from the system integration
module (SIM) enables the crystal oscillator circuit.
The CGMXCLK signal is the output of the crystal oscillator circuit and runs at a rate equal to the crystal
frequency. CGMXCLK is then buffered to produce CGMRCLK, the PLL reference clock.
CGMXCLK can be used by other modules which require precise timing for operation. The duty cycle of
CGMXCLK is not guaranteed to be 50% and depends on external factors, including the crystal and related
external components. An externally generated clock also can feed the OSC1 pin of the crystal oscillator
circuit. Connect the external clock to the OSC1 pin and let the OSC2 pin float.
8.3.2 Phase-Locked Loop Circuit (PLL)
The PLL is a frequency generator that can operate in either acquisition mode or tracking mode, depending
on the accuracy of the output frequency. The PLL can change between acquisition and tracking modes
either automatically or manually.
8.3.3 PLL Circuits
The PLL consists of these circuits:
Voltage-controlled oscillator (VCO)
Reference divider
Frequency prescaler
Modulo VCO frequency divider
Phase detector
Loop filter
Lock detector
The operating range of the VCO is programmable for a wide range of frequencies and for maximum
immunity to external noise, including supply and CGM/XFC noise. The VCO frequency is bound to a
range from roughly 40MHz to 56MHz, f
VRS
. Modulating the voltage on the CGM/XFC pin changes the
frequency within this range. By design, f
VRS
is tuned to a nominal center-of-range frequency of 48MHz.
CGMRCLK is the PLL reference clock, a buffered version of CGMXCLK. CGMRCLK runs at a frequency,
f
RCLK
, and is fed to the PLL through a programmable modulo reference divider, which divides f
RCLK
by a
factor R. This feature allows frequency steps of higher resolution. The divider’s output is the final
reference clock, CGMRDV, running at a frequency f
RDV
= f
/R.
The VCO’s output clock, CLK, running at a frequency f
VCLK
is fed back through a programmable prescale
divider and a programmable modulo divider. The prescaler divides the VCO clock by a power-of-two
factor P and the modulo divider reduces the VCO clock by a factor, N. The dividers’ output is the VCO
feedback clock, CGMVDV, running at a frequency f
VDV
= f
VCLK
/(N
×
2
P
). (See
8.3.6 Programming the PLL
for more information.)
The phase detector then compares the VCO feedback clock, CGMVDV, with the final reference clock,
CGMRDV. A correction pulse is generated based on the phase difference between the two signals. The
loop filter then slightly alters the DC voltage on the external capacitor connected to CGM/XFC based on
the width and direction of the correction pulse. The filter can make fast or slow corrections depending on
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MC68HC08LT8 | Microcontrollers |
| MC68HC08SR12 | M68HC08 Microcontrollers |
| MC68HC11E0 | HC11 Microcontrollers |
| MC68HC11K0 | HCMOS Microcontroller Unit |
| MC68HC11KMNPEVS | Microcontrollers |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MC68HC08KL8B | 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:General Release Specification |
| MC68HC08KL8FB | 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:General Release Specification |
| MC68HC08KX8 | 制造商:MOTOROLA 制造商全稱:Motorola, Inc 功能描述:Microcontrollers |
| MC68HC08LJ12 | 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:Addendum to MC68HC908LJ12 Technical Data |
| MC68HC08LJ12CFB | 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:Addendum to MC68HC908LJ12 Technical Data |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。