参数资料
| 型号： | PIC18LF4331T-I/ML |
| 厂商： | Microchip Technology |
| 文件页数： | 48/119页 |
| 文件大小： | 0K |
| 描述： | IC MCU FLASH 4KX16 44QFN |
| 标准包装： | 1,600 |
| 系列： | PIC® 18F |
| 核心处理器： | PIC |
| 芯体尺寸： | 8-位 |
| 速度： | 40MHz |
| 连通性： | I²C，SPI，UART/USART |
| 外围设备： | 欠压检测/复位，LVD，电源控制 PWM，QEI，POR，PWM，WDT |
| 输入/输出数： | 36 |
| 程序存储器容量： | 8KB（4K x 16） |
| 程序存储器类型： | 闪存 |
| EEPROM 大小： | 256 x 8 |
| RAM 容量： | 768 x 8 |
| 电压 - 电源 (Vcc/Vdd)： | 2 V ~ 5.5 V |
| 数据转换器： | A/D 9x10b |
| 振荡器型： | 内部 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 44-VQFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
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页当前第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页第92页第93页第94页第95页第96页第97页第98页第99页第100页第101页第102页第103页第104页第105页第106页第107页第108页第109页第110页第111页第112页第113页第114页第115页第116页第117页第118页第119页
PIC18F2331/2431/4331/4431
DS39616D-page 34
2010 Microchip Technology Inc.
3.7
Clock Sources and Oscillator
Switching
Like previous PIC18 devices, the PIC18F2331/2431/
4331/4431 devices include a feature that allows the sys-
tem clock source to be switched from the main oscillator
to an alternate low-frequency clock source. PIC18F2331/
2431/4331/4431 devices offer two alternate clock
sources. When enabled, these give additional options for
switching to the various power-managed operating
modes.
Essentially, there are three clock sources for these
devices:
Primary oscillators
Secondary oscillators
Internal oscillator block
The primary oscillators include the External Crystal
and Resonator modes, the External RC modes, the
External Clock modes and the internal oscillator block.
The particular mode is defined on POR by the contents
of Configuration Register 1H. The details of these
modes are covered earlier in this chapter.
The secondary oscillators are those external sources
not connected to the OSC1 or OSC2 pins. These
sources may continue to operate even after the
controller is placed in a power-managed mode.
PIC18F2331/2431/4331/4431 devices offer only the
Timer1 oscillator as a secondary oscillator. This
oscillator, in all power-managed modes, is often the
time base for functions such as a Real-Time Clock
(RTC).
Most often, a 32.768 kHz watch crystal is connected
between the RC0/T1OSO/T1CKI and RC1/T1OSI/
CCP2/FLTA pins. Like the LP Oscillator mode circuit,
loading capacitors are also connected from each pin to
ground.
The Timer1 oscillator is discussed in greater detail in
.
In addition to being a primary clock source, the internal
oscillator block
is available as a power-managed
mode clock source. The INTRC source is also used as
the clock source for several special features, such as
the WDT and Fail-Safe Clock Monitor.
The clock sources for the PIC18F2331/2431/4331/4431
devices are shown in Figure 3-8. See Section 13.0
for further details of the Timer1
oscillator. See Section 23.1 “Configuration Bits” for
Configuration register details.
3.7.1
OSCILLATOR CONTROL REGISTER
The OSCCON register (Register 3-2) controls sev-
eral aspects of the system clock’s operation, both in
full-power operation and in power-managed modes.
The System Clock Select bits, SCS<1:0>, select the
clock source that is used when the device is operating
in power-managed modes. The available clock sources
are the primary clock (defined in Configuration Register
1H), the secondary clock (Timer1 oscillator) and the
internal oscillator block. The clock selection has no
effect until a SLEEP instruction is executed and the
device enters a power-managed mode of operation.
The SCS bits are cleared on all forms of Reset.
The Internal Oscillator Select bits, IRCF<2:0>, select
the frequency output of the internal oscillator block that
is used to drive the system clock. The choices are the
INTRC source, the INTOSC source (8 MHz) or one of
the six frequencies derived from the INTOSC post-
scaler (125 kHz to 4 MHz). If the internal oscillator
block is supplying the system clock, changing the
states of these bits will have an immediate change on
the internal oscillator’s output. On device Resets, the
default output frequency of the internal oscillator block
is set at 32 kHz.
The OSTS, IOFS and T1RUN bits indicate which clock
source is currently providing the system clock. The OSTS
indicates that the Oscillator Start-up Timer has timed out,
and the primary clock is providing the system clock in
Primary Clock modes. The IOFS bit indicates when the
internal oscillator block has stabilized, and is providing
the system clock in RC Clock modes. The T1RUN bit
(T1CON<6>) indicates when the Timer1 oscillator is
providing the system clock in Secondary Clock modes. In
power-managed modes, only one of these three bits will
be set at any time. If none of these bits are set, the INTRC
is providing the system clock, or the internal oscillator
block has just started and is not yet stable.
The IDLEN bit controls the selective shutdown of the
controller’s CPU in power-managed modes. The use of
these bits is discussed in more detail in Section 4.0
Note 1:
The Timer1 oscillator must be enabled to
select the secondary clock source. The
Timer1 oscillator is enabled by setting the
T1OSCEN bit in the Timer1 Control
register (T1CON<3>). If the Timer1
oscillator is not enabled, then any
attempt to select a secondary clock
source,
when executing
a SLEEP
instruction, will be ignored.
2:
It is recommended that the Timer1
oscillator be operating and stable before
executing the SLEEP instruction, or a
very long delay may occur while the
Timer1 oscillator starts.
相关PDF资料 |
PDF描述 |
|---|---|
| PIC16C56A-04I/SO | IC MCU OTP 1KX12 18SOIC |
| PIC18F4515T-I/ML | IC MCU FLASH 24KX16 44QFN |
| PIC18F4515-E/PT | IC MCU FLASH 24KX16 44TQFP |
| PIC18F4515-E/ML | IC MCU FLASH 24KX16 44QFN |
| PIC18LF2610T-I/SO | IC MCU FLASH 32KX16 28SOIC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| PIC18LF43K22-E/ML | 功能描述:8位微控制器 -MCU 8KB Flash 3968b RAM SERIAL EE IND RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
| PIC18LF43K22-E/MV | 功能描述:8位微控制器 -MCU 8KB FL 512b RAM 8bit familynanoWatt XLP RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
| PIC18LF43K22-E/P | 功能描述:8位微控制器 -MCU 8KB Flash 3968b RAM SERIAL EE IND RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
| PIC18LF43K22-E/PT | 功能描述:8位微控制器 -MCU 8KB Flash 3968b RAM SERIAL EE IND RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
| PIC18LF43K22-I/ML | 功能描述:8位微控制器 -MCU 8KB Flash 3968b RAM SERIAL EE IND RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
发布紧急采购，3分钟左右您将得到回复。