參數(shù)資料
型號: MR80C52EXXX-12/883:R
廠商: TEMIC SEMICONDUCTORS
元件分類: 微控制器/微處理器
英文描述: 8-BIT, MROM, 12 MHz, MICROCONTROLLER, CQCC44
文件頁數(shù): 78/141頁
文件大?。?/td> 7628K
27
2486AA–AVR–02/2013
ATmega8(L)
Crystal Oscillator
XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier which can be con-
figured for use as an On-chip Oscillator, as shown in Figure 11. Either a quartz crystal or a
ceramic resonator may be used. The CKOPT Fuse selects between two different Oscillator
amplifier modes. When CKOPT is programmed, the Oscillator output will oscillate a full rail-to-
rail swing on the output. This mode is suitable when operating in a very noisy environment or
when the output from XTAL2 drives a second clock buffer. This mode has a wide frequency
range. When CKOPT is unprogrammed, the Oscillator has a smaller output swing. This reduces
power consumption considerably. This mode has a limited frequency range and it cannot be
used to drive other clock buffers.
For resonators, the maximum frequency is 8MHz with CKOPT unprogrammed and 16MHz with
CKOPT programmed. C1 and C2 should always be equal for both crystals and resonators. The
optimal value of the capacitors depends on the crystal or resonator in use, the amount of stray
capacitance, and the electromagnetic noise of the environment. Some initial guidelines for
choosing capacitors for use with crystals are given in Table 4. For ceramic resonators, the
capacitor values given by the manufacturer should be used.
Figure 11. Crystal Oscillator Connections
The Oscillator can operate in three different modes, each optimized for a specific frequency
range. The operating mode is selected by the fuses CKSEL3..1 as shown in Table 4.
Note:
1. This option should not be used with crystals, only with ceramic resonators
The CKSEL0 Fuse together with the SUT1..0 Fuses select the start-up times as shown in Table
Table 4. Crystal Oscillator Operating Modes
CKOPT
CKSEL3..1
Frequency Range
(MHz)
Recommended Range for Capacitors
C1 and C2 for Use with Crystals (pF)
1
0.4 - 0.9
1
110
0.9 - 3.0
12 - 22
1
111
3.0 - 8.0
12 - 22
0
101, 110, 111
1.0
12 - 22
XTAL2
XTAL1
GND
C2
C1
相關PDF資料
PDF描述
MR80C52XXX-12 8-BIT, MROM, 12 MHz, MICROCONTROLLER, CQCC44
MF180C51T-12D 8-BIT, MROM, 12 MHz, MICROCONTROLLER, PQFP44
MR80C32-12:D 8-BIT, 12 MHz, MICROCONTROLLER, CQCC44
MR80C32E-36:D 8-BIT, 36 MHz, MICROCONTROLLER, CQCC44
MR80C52TXXX-16SHXXX:R 8-BIT, MROM, 16 MHz, MICROCONTROLLER, CQCC44
相關代理商/技術參數(shù)
參數(shù)描述
MR80C86 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:CMOS 16-Bit Microprocessor
MR80C86/B 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Harris Corporation 功能描述:Microprocessor, 16 Bit, 44 Pin, Ceramic, LCC
MR80C86-2 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:CMOS 16-Bit Microprocessor
MR80C86-2/883 制造商:Rochester Electronics LLC 功能描述:- Bulk
MR80C86-2/B 制造商:Intersil Corporation 功能描述:MPU 80C86 16BIT CMOS 8MHZ 44PLCC - Rail/Tube