参数资料
型号: ST6252CB6/XXX
厂商: STMICROELECTRONICS
元件分类: 微控制器/微处理器
英文描述: 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDIP16
封装: 0.300 INCH, PLASTIC, DIP-16
文件页数: 8/75页
文件大小: 1753K
代理商: ST6252CB6/XXX
16/75
ST6252C ST6262B ST6262C
3 CLOCKS, RESET, INTERRUPTS AND POWER SAVING MODES
3.1 CLOCK SYSTEM
The MCU features a Main Oscillator which can be
driven by an external clock, or used in conjunction
with an AT-cut parallel resonant crystal or a suita-
ble ceramic resonator, or with an external resistor
(RNET). In addition, a Low Frequency Auxiliary Os-
cillator (LFAO) can be switched in for security rea-
sons, to reduce power consumption, or to offer the
benefits of a back-up clock system.
The Oscillator Safeguard (OSG) option filters
spikes from the oscillator lines, provides access to
the LFAO to provide a backup oscillator in the
event of main oscillator failure and also automati-
cally limits the internal clock frequency (fINT) as a
function of VDD, in order to guarantee correct oper-
ation. These functions are illustrated in Figure 9.,
Figure 8. illustrates various possible oscillator con-
figurations using an external crystal or ceramic res-
onator, an external clock input, an external resistor
(RNET), or the lowest cost solution using only the
LFAO. CL1 an CL2 should have a capacitance in the
range 12 tclkadcosgo 22 pF for an oscillator fre-
quency in the 4-8 MHz range.
The internal MCU clock frequency (fINT) is divided
by 12 to drive the Timer, the A/D converter and the
Watchdog timer, and by 13 to drive the CPU core,
as may be seen in Figure 11..
With an 8MHz oscillator frequency, the fastest ma-
chine cycle is therefore 1.625s.
A machine cycle is the smallest unit of time needed
to execute any operation (for instance, to increment
the Program Counter). An instruction may require
two, four, or five machine cycles for execution.
3.1.1 Main Oscillator
The oscillator configuration may be specified by se-
lecting the appropriate option. When the CRYS-
TAL/RESONATOR option is selected, it must be
used with a quartz crystal, a ceramic resonator or an
external signal provided on the OSCin pin. When the
RC NETWORK option is selected, the system clock
is generated by an external resistor.
The main oscillator can be turned off (when the
OSG ENABLED option is selected) by setting the
OSCOFF bit of the ADC Control Register. The
Low Frequency Auxiliary Oscillator is automatical-
ly started.
Figure 8. Oscillator Configurations
INTEGRATED CLOCK
CRYSTAL/RESONATOR option
OSG ENABLED option
OSCin
OSCout
CL1n
CL2
ST6xxx
CRYSTAL/RESONATOR CLOCK
CRYSTAL/RESONATOR option
OSCin
OSCout
ST6xxx
EXTERNAL CLOCK
CRYSTAL/RESONATOR option
NC
OSCin
OSCout
ST6xxx
NC
OSCin
OSCout
RNET
ST6xxx
RC NETWORK
RC NETWORK option
NC
相关PDF资料
PDF描述
ST62T62CM3 8-BIT, OTPROM, 8 MHz, MICROCONTROLLER, PDSO16
ST6252CM3/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDSO16
ST62T62CN6 8-BIT, OTPROM, 8 MHz, MICROCONTROLLER, PDSO16
ST62P62CB3/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDIP16
ST6252CN3/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDSO16
相关代理商/技术参数
参数描述
ST6252CM1 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:8-BIT OTP/EPROM MCUs WITH A/D CONVERTER, SAFE RESET, AUTO-RELOAD TIMER AND EEPROM
ST6252CM1/XXX 制造商:未知厂家 制造商全称:未知厂家 功能描述:MICROCONTROLLER|8-BIT|ST6200 CPU|CMOS|SOP|16PIN|PLASTIC
ST6252CM3 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:8-BIT OTP/EPROM MCUs WITH A/D CONVERTER, SAFE RESET, AUTO-RELOAD TIMER AND EEPROM
ST6252CM3/XXX 制造商:未知厂家 制造商全称:未知厂家 功能描述:8-Bit Microcontroller
ST6252CM6 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:8-BIT OTP/EPROM MCUs WITH A/D CONVERTER, SAFE RESET, AUTO-RELOAD TIMER AND EEPROM