- 您现在的位置：买卖IC网 > PDF目录84287 > R80C52EXXX-20:R (TEMIC SEMICONDUCTORS) 8-BIT, MROM, 20 MHz, MICROCONTROLLER, CQCC44 PDF资料下载
参数资料
| 型号： | R80C52EXXX-20:R |
| 厂商： | TEMIC SEMICONDUCTORS |
| 元件分类： | 微控制器/微处理器 |
| 英文描述： | 8-BIT, MROM, 20 MHz, MICROCONTROLLER, CQCC44 |
| 文件页数： | 23/91页 |
| 文件大小： | 19688K |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页当前第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页第82页第83页第84页第85页第86页第87页第88页第89页第90页第91页
34
7707F–AVR–11/10
AT90USB82/162
6.6
External Clock
The device can utilize a external clock source as shown in Figure 6-5. To run the device on an
external clock, the CKSEL Fuses must be programmed as shown in Table 6-1.
Figure 6-5.
External Clock Drive Configuration
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
When applying an external clock, it is required to avoid sudden changes in the applied clock fre-
quency to ensure stable operation of the MCU. A variation in frequency of more than 2% from
one clock cycle to the next can lead to unpredictable behavior. If changes of more than 2% is
required, ensure that the MCU is kept in Reset during the changes.
Note that the System Clock Prescaler can be used to implement run-time changes of the internal
clock frequency while still ensuring stable operation. Refer to “System Clock Prescaler” on page
34 for details.
6.7
Clock Output Buffer
The device can output the system clock on the CLKO pin. To enable the output, the CKOUT
Fuse has to be programmed. This mode is suitable when the chip clock is used to drive other cir-
cuits on the system. The clock also will be output during reset, and the normal operation of I/O
pin will be overridden when the fuse is programmed. Any clock source, including the internal RC
Oscillator, can be selected when the clock is output on CLKO. If the System Clock Prescaler is
used, it is the divided system clock that is output.
6.8
System Clock Prescaler
The AT90USB82/162 has a system clock prescaler, and the system clock can be divided by set-
ting the “Clock Prescale Register – CLKPR” on page 35. This feature can be used to decrease
Table 6-8.
Start-up Times for the External Clock Selection
Power Conditions
Start-up Time from Power-
down and Power-save
Additional Delay from
Reset (VCC = 5.0V)
SUT1..0
BOD enabled
6 CK
14CK
00
Fast rising power
6 CK
14CK + 4.1 ms
01
Slowly rising power
6 CK
14CK + 65 ms
10
Reserved
11
NC
EXTERNAL
CLOCK
SIGNAL
XTAL2
XTAL1
GND
相关PDF资料 |
PDF描述 |
|---|---|
| R80C52EXXX-20SHXXX | 8-BIT, MROM, 20 MHz, MICROCONTROLLER, CQCC44 |
| R80C52EXXX-25:RD | 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CQCC44 |
| R80C52EXXX-25 | 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CQCC44 |
| R80C52EXXX-30SHXXX:RD | 8-BIT, MROM, 30 MHz, MICROCONTROLLER, CQCC44 |
| R80C52EXXX-30 | 8-BIT, MROM, 30 MHz, MICROCONTROLLER, CQCC44 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| R80ES11WES | 制造商:UNBRANDED 功能描述:LAMP ENERGY SAVING R80 11W ES |
| R80M | 制造商:Omron Corporation 功能描述: |
| R80P | 制造商:Orion Fans 功能描述:Filter Kit; Retainer only; ABS UL94V-0; Fits 80mm Fan; 83.6mm W; 9.8mm D |
| R80X5200CK | 制造商:Samsung Semiconductor 功能描述:100 Pack 52x80 Minute CD-R Media |
| R8-10 | 制造商:JST Manufacturing 功能描述:8AWG 29.8mm 15mm 制造商:JST Manufacturing 功能描述:Terminal,R8-10 |
发布紧急采购，3分钟左右您将得到回复。