Datasheet
Table Of Contents
- High-Performance RISC CPU:
- Special Microcontroller Features:
- Low-Power Features/CMOS Technology:
- Peripheral Features:
- Table of Contents
- Most Current Data Sheet
- Errata
- Customer Notification System
- 1.0 General Description
- 2.0 PIC12F519 Device Varieties
- 3.0 Architectural Overview
- 4.0 Memory Organization
- 5.0 Flash Data Memory Control
- 6.0 I/O Port
- 7.0 Timer0 Module and TMR0 Register
- 8.0 Special Features Of The CPU
- 8.1 Configuration Bits
- 8.2 Oscillator Configurations
- 8.3 Reset
- 8.4 Power-on Reset (POR)
- 8.5 Device Reset Timer (DRT)
- 8.6 Watchdog Timer (WDT)
- 8.7 Time-out Sequence, Power-down and Wake-up from Sleep Status Bits (TO, PD, GPWUF)
- 8.8 Power-down Mode (Sleep)
- 8.9 Program Verification/Code Protection
- 8.10 ID Locations
- 8.11 In-Circuit Serial Programming™
- 9.0 Instruction Set Summary
- 10.0 Development Support
- 10.1 MPLAB Integrated Development Environment Software
- 10.2 MPASM Assembler
- 10.3 MPLAB C18 and MPLAB C30 C Compilers
- 10.4 MPLINK Object Linker/ MPLIB Object Librarian
- 10.5 MPLAB ASM30 Assembler, Linker and Librarian
- 10.6 MPLAB SIM Software Simulator
- 10.7 MPLAB ICE 2000 High-Performance In-Circuit Emulator
- 10.8 MPLAB REAL ICE In-Circuit Emulator System
- 10.9 MPLAB ICD 2 In-Circuit Debugger
- 10.10 MPLAB PM3 Device Programmer
- 10.11 PICSTART Plus Development Programmer
- 10.12 PICkit 2 Development Programmer
- 10.13 Demonstration, Development and Evaluation Boards
- 11.0 Electrical Characteristics
- Absolute Maximum Ratings(†)
- 11.1 DC Characteristics
- 11.2 Timing Parameter Symbology and Load Conditions – PIC12F519
- 11.3 AC Characteristics
- TABLE 11-5: External Clock Timing Requirements
- TABLE 11-6: Calibrated Internal RC Frequencies
- FIGURE 11-5: I/O Timing
- TABLE 11-7: Timing Requirements
- FIGURE 11-6: Reset, Watchdog Timer and Device Reset Timer Timing
- TABLE 11-8: Reset, Watchdog Timer and Device Reset Timer – PIC12F519
- TABLE 11-9: DRT (Device Reset Timer Period)
- FIGURE 11-7: Timer0 Clock Timings
- TABLE 11-10: Timer0 Clock Requirements
- TABLE 11-11: Flash Data Memory Write/Erase Requirements
- 12.0 DC and AC Characteristics Graphs and Charts
- FIGURE 12-1: Typical Idd vs. Fosc Over Vdd (XT, EXTRC mode)
- FIGURE 12-2: Maximum Idd vs. Fosc Over Vdd (XT, EXTRC mode)
- FIGURE 12-3: Idd vs. Vdd over fosc (LP Mode)
- FIGURE 12-4: Typical Ipd vs. Vdd (Sleep Mode, all Peripherals Disabled)
- FIGURE 12-5: Maximum Ipd vs. Vdd (Sleep Mode, all Peripherals Disabled)
- FIGURE 12-6: Typical WDT Ipd VS. Vdd
- FIGURE 12-7: Maximum WDT Ipd VS. Vdd Over Temperature
- FIGURE 12-8: WDT TIME-OUT VS. Vdd Over Temperature (No Prescaler)
- FIGURE 12-9: Vol VS. Iol Over Temperature (Vdd = 3.0V)
- FIGURE 12-10: Vol VS. Iol Over Temperature (Vdd = 5.0V)
- FIGURE 12-11: Voh VS. Ioh Over Temperature (Vdd = 3.0V)
- FIGURE 12-12: Voh VS. Ioh Over Temperature (Vdd = 5.0V)
- FIGURE 12-13: TTL Input Threshold Vin VS. Vdd
- FIGURE 12-14: Schmitt Trigger Input Threshold Vin VS. Vdd
- FIGURE 12-15: Device Reset Timer (XT and LP) vs. Vdd
- 13.0 Packaging Information
- Appendix A: Revision History
- INDEX
- The Microchip Web Site
- Customer Change Notification Service
- Customer Support
- Reader Response
- Product Identification System
- Worldwide Sales
PIC12F519
DS41319B-page 34 © 2008 Microchip Technology Inc.
7.2 Prescaler
An 8-bit counter is available as a prescaler for the
Timer0 module or as a postscaler for the Watchdog
Timer (WDT), respectively (see Section 8.6 “Watch-
dog Timer (WDT)”). For simplicity, this counter is
being referred to as “prescaler” throughout this data
sheet.
The PSA and PS<2:0> bits (OPTION<3:0>) determine
prescaler assignment and prescale ratio.
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (e.g., CLRF TMR0,
MOVWF TMR0, etc.) will clear the prescaler. When
assigned to WDT, a CLRWDT instruction will clear the
prescaler along with the WDT. The prescaler is neither
readable nor writable. On a Reset, the prescaler con-
tains all ‘0’s.
7.2.1 SWITCHING PRESCALER
ASSIGNMENT
The prescaler assignment is fully under software
control (i.e., it can be changed “on-the-fly” during pro-
gram execution). To avoid an unintended device Reset,
the following instruction sequence (Example 7-1) must
be executed when changing the prescaler assignment
from Timer0 to the WDT.
EXAMPLE 7-1: CHANGING PRESCALER
(TIMER0 → WDT)
To change the prescaler from the WDT to the Timer0
module, use the sequence shown in Example 7-2. This
sequence must be used even if the WDT is disabled. A
CLRWDT instruction should be executed before
switching the prescaler.
EXAMPLE 7-2: CHANGING PRESCALER
(WDT → TIMER0)
Note: The prescaler may be used by either the
Timer0 module or the WDT, but not both.
Thus, a prescaler assignment for the
Timer0 module means that there is no
prescaler for the WDT and vice versa.
CLRWDT ;Clear WDT
CLRF TMR0 ;Clear TMR0 and Prescaler
MOVLW b‘00xx1111’
OPTION
CLRWDT ;PS<2:0> are 000 or 001
MOVLW b‘00xx1xxx’ ;Set Postscaler to
OPTION ;desired WDT rate
CLRWDT ;Clear WDT and
;prescaler
MOVLW b‘xxxx0xxx’ ;Select TMR0, new
;prescale value and
;clock source
OPTION