dsPIC30F
7.0
SYSTEM INTEGRATION
7.2
Power-On Reset
System management services provided by the
dsPIC30F device family include:
When a supply voltage is applied to the device, a
Power-on Reset is generated. A new Power-on Reset
?
?
?
?
Control of clock options and oscillators
Power-on Reset
Programmable Brown-out Reset
Program control of Power-up Timer
event is generated if the supply voltage falls below the
device threshold voltage (V POR ). An internal POR
pulse is generated when the rising supply voltage
crosses the POR circuit threshold voltage.
?
Oscillator start-up timer/stabilizer
7.3
Programmable Brown-out Reset
?
?
?
Watchdog Timer with RC oscillator
Fail-Safe Clock Monitor
Reset by multiple sources
The BOR (Brown-out Reset) module is based on an
internal voltage reference circuit. The main purpose of
the BOR module is to generate a device Reset when a
brown-out condition occurs. Brown-out conditions are
7.1
Clock Options and Oscillators
generally caused by glitches on the AC mains (i.e.,
There are three primary clock oscillators: XTL, XT and
HS. The XTL oscillator is designed for crystals or
ceramic resonators in the range of 200 kHz to 4 MHz.
The XT oscillator is designed for crystals and ceramic
resonators in the range of 4 to 10 MHz. The HS (High-
Speed) oscillator is for crystals in the 10 to 25 MHz
missing portions of the AC cycle waveform due to bad
power transmission lines or voltage sags due to
excessive current draw when a large inductive load is
turned on).
The BOR module allows selection of one of the
following voltage trip points:
range. These oscillators use the OSC1 and OSC2 pins.
The secondary (LP) oscillator is designed for low power
and uses a 32 kHz crystal or ceramic resonator. The LP
oscillator uses the SOSC1 and SOSC2 pins.
?
?
?
?
2.0V
2.7V
4.2V
4.5V
The FRC (Fast RC) internal oscillator runs at a nominal
Note:
The BOR voltage trip points indicated here
7.37 MHz ±2%. The user software can tune the FRC
frequency. The LPRC (Low Power RC) internal
oscIllator is connected to the Watchdog Timer, and it
runs at a nominal 512 kHz. The External RC (ERC)
oscillator uses an external resistor and capacitor
connected to the OSC1 pin. Frequency of operation is
up to 4 MHz.
The OSC1 pin can also be used as an input from an
external clock source; this mode is called “EC”.
The dsPIC30F oscillator system provides:
? Various external and internal oscillator options as
clock sources
? An on-chip PLL to boost internal operating
frequency 4, 8 or 16 times
? In some devices, the FRC oscillator can also be
used with the PLL
? Clock switching between various clock sources
? Programmable clock postscaler for system power
savings
? A Fail-Safe Clock Monitor (FSCM) that detects
clock failure and takes fail-safe measures
? A Clock Control register (OSCCON)
? Nonvolatile Configuration bits for main oscillator
selection.
A simplified block diagram of the oscillator system is
shown in Figure 7-1.
? 2005 Microchip Technology Inc.
are nominal values provided for design
guidance only. Refer to the Electrical
Specifications in the specific device data
sheet for BOR voltage limit specifications.
A BOR generates a Reset pulse, which resets the
device.
DS70043F-page 19
相关PDF资料
MA320002 MODULE PLUG-IN PIC32 USB OTG
MA320011 MODULE PLUG-IN PIC32MX220F32D
MA330024 MODULE PLUG-IN DSPIC33F 100TQFP
MA330027 MODULE PLUG-IN DSPIC33F 100TQFP
MA330029 MODULE PLUG-IN DSPIC33FJ16GP102
MA9D00-42 DSUB CONN W/DIAGNOSTIC PORT STRT
MAI ADAPTER PUSH-ON/M-SWTCH ATTCHMNT
MAV0020RP VARISTOR ARRY 2ELEMENT 120V 0405
相关代理商/技术参数
MA300013 制造商:Microchip Technology Inc 功能描述:Tools Development kit Kit Con
MA300014 功能描述:子卡和OEM板 dsPIC30F 80L Plug In Sample (6014A) RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit
MA300015 功能描述:子卡和OEM板 dsPIC30F 80L Plug In Sample (6010A). RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit
MA300016 功能描述:子卡和OEM板 dsPICDEM 80-PIN PIM RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit
MA300118 功能描述:子卡和OEM板 _ RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit
MA300128 功能描述:子卡和OEM板 _ RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit
MA300140 功能描述:子卡和OEM板 _ RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit
MA300228 功能描述:子卡和OEM板 _ RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit