FIGURE 8-11: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO V
參數(shù)資料
型號: PIC12C508-04/P
廠商: Microchip Technology
文件頁數(shù): 51/113頁
文件大?。?/td> 0K
描述: IC MCU OTP 512X12 8DIP
產(chǎn)品培訓(xùn)模塊: Asynchronous Stimulus
8-bit PIC® Microcontroller Portfolio
標(biāo)準(zhǔn)包裝: 60
系列: PIC® 12C
核心處理器: PIC
芯體尺寸: 8-位
速度: 4MHz
外圍設(shè)備: POR,WDT
輸入/輸出數(shù): 5
程序存儲器容量: 768B(512 x 12)
程序存儲器類型: OTP
RAM 容量: 25 x 8
電壓 - 電源 (Vcc/Vdd): 2.5 V ~ 5.5 V
振蕩器型: 內(nèi)部
工作溫度: 0°C ~ 70°C
封裝/外殼: 8-DIP(0.300",7.62mm)
包裝: 管件
配用: DVMCPA-ND - KIT DVR BOARD EVAL SYSTEM MXDEV1
DVA12XP080-ND - ADAPTER DEVICE FOR MPLAB-ICE
AC124001-ND - MODULE SKT PROMATEII 8DIP/SOIC
PIC12C5XX
DS40139E-page 42
1999 Microchip Technology Inc.
FIGURE 8-11: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD): SLOW VDD RISE TIME
VDD
MCLR
INTERNAL POR
DRT TIME-OUT
INTERNAL RESET
TDRT
V1
When VDD rises slowly, the TDRT time-out expires long before VDD has reached its final value. In
this example, the chip will reset properly if, and only if, V1
≥ VDD min.
8.5
Device Reset Timer (DRT)
In the PIC12C5XX, DRT runs from RESET and varies
based on oscillator selection (see Table 8-5.)
The DRT operates on an internal RC oscillator. The
processor is kept in RESET as long as the DRT is
active. The DRT delay allows VDD to rise above VDD
min., and for the oscillator to stabilize.
Oscillator circuits based on crystals or ceramic
resonators require a certain time after power-up to
establish a stable oscillation. The on-chip DRT keeps
the device in a RESET condition for approximately 18
ms after MCLR has reached a logic high (VIHMCLR)
level. Thus, programming GP3/MCLR/VPP as MCLR
and using an external RC network connected to the
MCLR input is not required in most cases, allowing for
savings in cost-sensitive and/or space restricted
applications, as well as allowing the use of the GP3/
MCLR/VPP pin as a general purpose input.
The Device Reset time delay will vary from chip to chip
due to VDD, temperature, and process variation. See
AC parameters for details.
The DRT will also be triggered upon a Watchdog
Timer time-out. This is particularly important for
applications using the WDT to wake from SLEEP
mode automatically.
8.6
Watchdog Timer (WDT)
The Watchdog Timer (WDT) is a free running on-chip
RC oscillator which does not require any external
components. This RC oscillator is separate from the
external RC oscillator of the GP5/OSC1/CLKIN pin
and the internal 4 MHz oscillator. That means that the
WDT will run even if the main processor clock has
been stopped, for example, by execution of a SLEEP
instruction. During normal operation or SLEEP, a WDT
reset or wake-up reset generates a device RESET.
The TO bit (STATUS<4>) will be cleared upon a
Watchdog Timer reset.
The
WDT
can
be
permanently
disabled
by
programming the configuration bit WDTE as a ’0’
(Section 8.1). Refer to the PIC12C5XX Programming
Specifications to determine how to access the
configuration word.
TABLE 8-5:
DRT (DEVICE RESET TIMER
PERIOD)
Oscillator
Configuration
POR Reset
Subsequent
Resets
IntRC &
ExtRC
18 ms (typical)
300 s (typical)
XT & LP
18 ms (typical)
相關(guān)PDF資料
PDF描述
22-15-3153 CONN FFC/FPC 15POS .100 RT ANG
PIC16F1826-I/MV IC PIC MCU FLASH 2K 28-UQFN
PIC16F1825-I/P MCU PIC 14K FLASH 1K RAM 14DIP
22-02-3153 CONN FFC/FPC VERTICAL 15POS .100
22-15-3143 CONN FFC/FPC 14POS .100 RT ANG
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PIC12C508A 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontrollers
PIC12C508A/JW 功能描述:8位微控制器 -MCU .75KB 25 RAM 6 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
PIC12C508A-04/EJW 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontrollers
PIC12C508A-04/EP 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontrollers
PIC12C508A-04/ESM 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontrollers