Description
PIC18LF2321 offers the advantages of all PIC18 microcontrollers – namely, high computational performance at an economical price – with the addition of highendurance, Enhanced Flash program memory. On top of these features, the PIC18F2221/2321/4221/4321 family introduces design enhancements that make these microcontrollers a logical choice for many high-performance, power sensitive applications All of the devices in the PIC18F2221/2321/4221/4321 family incorporate a range of features that can significantly reduce power consumption during operation. Alternate Run Modes: By clocking the controller from the Timer1 source or the internal oscillator block, power consumption during code execution can be reduced by as much as 90%. Multiple Idle Modes: The controller can also run with its CPU core disabled but the peripherals still active. In these states, power consumption can be reduced even further, to as little as 4% of normal operation requirements. On-the-Fly Mode Switching: The power-managed modes are invoked by user code during operation, allowing the user to incorporate power-saving ideas into their application’s software design. Low Consumption in Key Modules: The power requirements for both Timer1 and the Watchdog Timer are minimized. All of the devices in the PIC18F2221/2321/4221/4321 family offer ten different oscillator options, allowing users a wide range of choices in developing application hardware. Four Crystal modes, using crystals or ceramic resonators. Two External Clock modes, offering the option of using two pins (oscillator input and a divide-by-4 clock output) or one pin (oscillator input, with the second pin reassigned as general I/O). Two External RC Oscillator modes with the same pin options as the External Clock modes. Two Internal Oscillator modes which provide an 8 MHz clock and an INTRC source (approximately 31 kHz), as well as a range of 6 user-selectable clock frequencies, between 125 kHz to 4 MHz, for a total of 8 clock frequencies. One or both of the oscillator pins can be used for general purpose I/O. A Phase Lock Loop (PLL) frequency multiplier, available to both the high-speed crystal and internal oscillator modes, which allows clock speeds of up to 40 MHz. Used with the internal oscillator, the PLL gives users a complete selection of clock speeds, from 31 kHz to 32 MHz – all without using an external crystal or clock circuit Besides its availability as a clock source, the internal oscillator block provides a stable reference source that gives the family additional features for robust operation: Fail-Safe Clock Monitor: This option constantly monitors the main clock source against a reference signal provided by the internal oscillator. If a clock failure occurs, the controller is switched to the internal oscillator block, allowing for continued low-speed operation or a safe application shutdown Two-Speed Start-up: This option allows the internal oscillator to serve as the clock source from Power-on Reset, or wake-up from Sleep mode, until the primary clock source is available
- Power-Managed Modes:
- Run: CPU On, Peripherals On
- Idle: CPU Off, Peripherals On
- Sleep: CPU Off, Peripherals Off
- Idle mode Currents Down to 2.5 µA Typical
- Sleep mode Currents Down to 500 nA Typical
- Timer1 Oscillator: 1.8 µA, 32 kHz, 2V Typical
- Watchdog Timer: 1.6 µA, 2V Typical
- Two-Speed Oscillator Start-up
- Flexible Oscillator Structure:
- Four Crystal modes, up to 40 MHz
- 4x Phase Lock Loop (PLL) – Available for Crystal and Internal Oscillators
- Two External RC modes, up to 4 MHz
- Two External Clock modes, up to 40 MHz
- Internal Oscillator Block:
- 8 user-selectable frequencies, from 31 kHz to 8 MHz
- Provides a complete range of clock speeds from 31 kHz to 32 MHz when used with PLL
- User-tunable to compensate for frequency drift
- Secondary Oscillator using Timer1 @ 32 kHz
- Fail-Safe Clock Monitor
- Allows for safe shutdown if peripheral clock stops
- Peripheral Highlights:
- High-Current Sink/Source 25 mA/25 mA
- Three Programmable External Interrupts
- Four Input Change Interrupts
- Up to 2 Capture/Compare/PWM (CCP) modules, one with Auto-Shutdown (28-pin devices)
- Enhanced Capture/Compare/PWM (ECCP) module (40/44-pin devices only):
- One, two or four PWM outputs
- Selectable polarity
- Programmable dead time
- Auto-shutdown and auto-restart
- Master Synchronous Serial Port (MSSP) module Supporting 3-Wire SPI (all 4 modes) and I2C™ Master and Slave modes
- Enhanced Addressable USART module:
- Supports RS-485, RS-232 and LIN/J2602
- Auto-wake-up on Start bit
- Auto-Baud Detect
- 10-Bit, up to 13-Channel Analog-to-Digital Converter module (A/D):
- Auto-acquisition capability
- Conversion available during Sleep
- Dual Analog Comparators with Input Multiplexing
- Programmable 16-Level High/Low-Voltage Detection (HLVD) module:
- Supports interrupt on High/Low-Voltage Detection
- Special Microcontroller Features:
- C Compiler Optimized Architecture:
- Optional extended instruction set designed to optimize re-entrant code
- 100,000 Erase/Write Cycle Enhanced Flash Program Memory Typical
- 1,000,000 Erase/Write Cycle Data EEPROM Memory Typical
- Flash/Data EEPROM Retention: 100 Years Typical
- Self-Programmable under Software Control
- Priority Levels for Interrupts
- 8 x 8 Single-Cycle Hardware Multiplier
- Extended Watchdog Timer (WDT):
- Programmable period from 4 ms to 131s
- Single-Supply 5V In-Circuit Serial Programming™ (ICSP™) via Two Pins
- In-Circuit Debug (ICD) via Two Pins
- Wide Operating Voltage Range: 2.0V to 5.5V
- Programmable Brown-out Reset (BOR) with Software Enable Option)
