- 您現在的位置：買賣IC網 > PDF目錄371043 > MC68332 (Motorola, Inc.) 32-Bit Modular Microcontroller PDF資料下載
參數資料
| 型號： | MC68332 |
| 廠商： | Motorola, Inc. |
| 英文描述： | 32-Bit Modular Microcontroller |
| 中文描述： | 32位微控制器模塊 |
| 文件頁數： | 24/88頁 |
| 文件大?。?/td> | 446K |
| 代理商： | MC68332 |
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頁當前第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
MOTOROLA
24
MC68332
MC68332TS/D
When an external system clock signal is applied (i.e., the PLL is not used), duty cycle of the input is
critical, especially at near maximum operating frequencies. The relationship between clock signal duty
cycle and clock signal period is expressed:
Minimum external clock period =
minimum external clock high/low time
50% — percentage variation of external clock input duty cycle
3.3.2 Clock Synthesizer Operation
A voltage controlled oscillator (VCO) generates the system clock signal. A portion of the clock signal is
fed back to a divider/counter. The divider controls the frequency of one input to a phase comparator.
The other phase comparator input is a reference signal, either from the internal oscillator or from an
external source. The comparator generates a control signal proportional to the difference in phase be-
tween its two inputs. The signal is low-pass filtered and used to correct VCO output frequency.
The synthesizer locks when VCO frequency is identical to reference frequency. Lock time is affected by
the filter time constant and by the amount of difference between the two comparator inputs. Whenever
comparator input changes, the synthesizer must re-lock. Lock status is shown by the SLOCK bit in SYN-
CR.
The MCU does not come out of reset state until the synthesizer locks. Crystal type, characteristic fre-
quency, and layout of external oscillator circuitry affect lock time.
The low-pass filter requires an external low-leakage capacitor, typically 0.1
μ
F, connected between the
XFC and V
DDSYN
pins.
V
DDSYN
is used to power the clock circuits. A separate power source increases MCU noise immunity
and can be used to run the clock when the MCU is powered down. Use a quiet power supply as the
V
DDSYN
source, since PLL stability depends on the VCO, which uses this supply. Place adequate ex-
ternal bypass capacitors as close as possible to the V
DDSYN
pin to ensure stable operating frequency.
When the clock synthesizer is used, control register SYNCR determines operating frequency and vari-
ous modes of operation. SYNCR can be read only when the processor is operating at the supervisor
privilege level.
The SYNCR X bit controls a divide by two prescaler that is not in the synthesizer feedback loop. Setting
X doubles clock speed without changing VCO speed. There is no VCO relock delay. The SYNCR W bit
controls a 3-bit prescaler in the feedback divider. Setting W increases VCO speed by a factor of four.
The SYNCR Y field determines the count modulus for a modulo 64 down counter, causing it to divide
by a value of Y
+
1. When either W or Y value changes, there is a VCO relock delay.
Clock frequency is determined by SYNCR bit settings as follows:
F
SYSTEM
= F
REFERENCE
[4(Y + 1)(2
2W + X
)]
In order for the device to perform correctly, the clock frequency selected by the W, X, and Y bits must
be within the limits specified for the MCU.
The VCO frequency is twice the system clock frequency if X = 1 or four times the system clock frequency
if X = 0.
The reset state of SYNCR ($3F00) produces a modulus-64 count.
相關PDF資料 |
PDF描述 |
|---|---|
| MC68332ACFC16 | 32-Bit Modular Microcontroller |
| MC68332ACFC20 | 32-Bit Modular Microcontroller |
| MC68332ACFV16 | 32-Bit Modular Microcontroller |
| MC68332ACFV20 | 32-Bit Modular Microcontroller |
| MC68332AMFC16 | 32-Bit Modular Microcontroller |
相關代理商/技術參數 |
參數描述 |
|---|---|
| MC683326CFC16 | 制造商:Motorola Inc 功能描述: |
| MC68332ACAG16 | 功能描述:32位微控制器 - MCU 32B MCU 2KRAM TPU QSM RoHS:否 制造商:Texas Instruments 核心:C28x 處理器系列:TMS320F28x 數據總線寬度:32 bit 最大時鐘頻率:90 MHz 程序存儲器大小:64 KB 數據 RAM 大小:26 KB 片上 ADC:Yes 工作電源電壓:2.97 V to 3.63 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:LQFP-80 安裝風格:SMD/SMT |
| MC68332ACAG16 | 制造商:Freescale Semiconductor 功能描述:32-Bit Microcontroller IC |
| MC68332ACAG16B1 | 制造商:Freescale Semiconductor 功能描述: |
| MC68332ACAG20 | 功能描述:32位微控制器 - MCU 32B MCU 2KRAM TPU QSM RoHS:否 制造商:Texas Instruments 核心:C28x 處理器系列:TMS320F28x 數據總線寬度:32 bit 最大時鐘頻率:90 MHz 程序存儲器大小:64 KB 數據 RAM 大小:26 KB 片上 ADC:Yes 工作電源電壓:2.97 V to 3.63 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:LQFP-80 安裝風格:SMD/SMT |
發布緊急采購，3分鐘左右您將得到回復。