PIC16F1936-I/SO

Product Overview of the PIC16(L)F1936 Microcontroller

The PIC16(L)F1936 represents a member of Microchip Technology's PIC16 family of 8-bit CMOS microcontrollers, specifically engineered for applications requiring integrated LCD display control combined with ultra-low power operation. This device integrates a comprehensive set of peripherals within a compact 28-pin package, making it suitable for battery-powered consumer electronics, industrial instrumentation, and portable medical devices.

The PIC16(L)F1936 is available in two voltage variants: the standard PIC16F1936 operating across 1.8V to 5.5V, and the low-power PIC16LF1936 optimized for 1.8V to 3.6V operation. Both variants share identical instruction sets and peripheral configurations, allowing designers to select the appropriate version based on their power supply architecture. The device incorporates Microchip's nanoWatt XLP technology, a power management architecture that enables standby currents as low as 60 nanoamperes at 1.8V while maintaining full system functionality upon wake-up.

Core Architecture and Processing Capabilities of the PIC16(L)F1936

The PIC16(L)F1936 employs a high-performance Reduced Instruction Set Computer (RISC) architecture optimized for embedded control applications. The instruction set comprises only 49 instructions, with all operations executing as single-cycle instructions except for branch operations, which require two instruction cycles. This streamlined instruction set reduces the learning curve for developers while maintaining sufficient functionality for complex control algorithms.

The processor operates at clock frequencies ranging from DC to 32 MHz, providing instruction cycle times as fast as 125 nanoseconds at maximum clock speed. This performance envelope allows the device to handle real-time control tasks, signal processing, and communication protocol implementations without requiring external coprocessors. The architecture supports three addressing modes—direct, indirect, and relative—enabling flexible memory access patterns for different programming paradigms.

The device incorporates a 16-level deep hardware stack for subroutine calls and interrupt handling, allowing nested function calls up to 16 levels deep. This stack depth accommodates moderately complex firmware architectures with multiple interrupt service routines and layered function calls without requiring software-based stack management.

Memory Organization and Data Storage in the PIC16(L)F1936

The PIC16(L)F1936 integrates three distinct memory spaces: Flash program memory, EEPROM data memory, and SRAM working memory. The Flash program memory provides 8192 words (14 bits per word), yielding approximately 14 kilobytes of storage for application firmware. This capacity accommodates moderate-complexity control algorithms, state machines, and communication protocol handlers.

The EEPROM data memory consists of 256 bytes, providing non-volatile storage for configuration parameters, calibration constants, and user data that must persist across power cycles. The EEPROM supports 1,000,000 write cycles per byte, enabling applications that require frequent parameter updates such as energy meters, data loggers, and adaptive control systems.

The SRAM working memory provides 512 bytes for runtime variables, stack operations, and peripheral register access. This memory space is organized into general-purpose registers and special-function registers that control peripheral operation and device configuration.

Both Flash and EEPROM memory employ high-endurance cell technology with retention specifications exceeding 40 years, ensuring data integrity throughout the product lifetime. The Flash memory supports 100,000 write cycles per location, sufficient for firmware updates during manufacturing and field service operations.

Power Management and Energy Efficiency Features of the PIC16(L)F1936

The PIC16(L)F1936 incorporates multiple power management features enabling operation in battery-powered applications with extended runtime between charging cycles. The standby current consumption reaches 60 nanoamperes at 1.8V in the low-power variant, representing a reduction of several orders of magnitude compared to conventional microcontrollers. This ultra-low standby current allows devices to remain powered indefinitely from small coin-cell batteries while maintaining real-time clock functionality.

During active operation at 32 kHz clock frequency and 1.8V supply, the PIC16LF1936 consumes approximately 7.0 microamperes, enabling battery-powered devices to operate for months or years on a single charge. At higher clock frequencies such as 1 MHz and 1.8V supply, the operating current increases to approximately 150 microamperes, still representing efficient power utilization for applications requiring moderate processing performance.

The device incorporates a Power-on Reset (POR) circuit that automatically initializes the microcontroller when supply voltage rises above the POR threshold, eliminating the need for external reset circuitry. The Power-up Timer (PWRT) delays code execution for a programmable interval following power-on, allowing the oscillator and power supply to stabilize before the processor begins executing instructions.

A Brown-out Reset (BOR) circuit monitors the supply voltage and forces a device reset if the voltage drops below a selectable threshold, protecting against data corruption and erratic behavior during power supply transients. The BOR function includes two selectable trip points, allowing designers to choose the reset threshold appropriate for their specific power supply architecture.

The device incorporates a Power-Saving Sleep mode that halts the main processor clock while maintaining operation of selected peripherals such as the watchdog timer and Timer1 oscillator. In Sleep mode, current consumption drops to the standby level, allowing the device to remain responsive to external interrupts or timer events while consuming minimal power.

Oscillator and Timing Systems in the PIC16(L)F1936

The PIC16(L)F1936 provides multiple oscillator options to accommodate different application requirements and cost constraints. The precision internal oscillator operates across a software-selectable frequency range from 31 kHz to 32 MHz, with factory calibration to ±1% accuracy. This internal oscillator eliminates the need for external crystal components in many applications, reducing board space and component cost.

The internal oscillator incorporates a dedicated low-power 32 kHz oscillator driver, enabling real-time clock applications with minimal power consumption. The 32 kHz oscillator consumes approximately 600 nanoamperes at 1.8V, allowing battery-powered devices to maintain accurate timekeeping while in Sleep mode.

The device supports external oscillator inputs for applications requiring higher frequency stability or operation at frequencies not available from the internal oscillator. The external oscillator input accepts clock signals from DC to 32 MHz, accommodating crystal oscillators, ceramic resonators, and external clock sources.

The Oscillator Start-up Timer (OST) provides a programmable delay following oscillator startup, ensuring that the oscillator has stabilized before the processor begins executing instructions. This feature prevents instruction execution errors that could occur if the processor clock frequency has not yet reached the programmed value.

Analog Signal Processing and Conversion in the PIC16(L)F1936

The PIC16(L)F1936 integrates a 10-bit analog-to-digital converter (ADC) with up to 14 selectable input channels, enabling the device to measure analog signals from sensors, transducers, and other analog sources. The ADC provides 10-bit resolution, yielding 1024 discrete output levels across the selected voltage reference range.

The ADC incorporates selectable voltage reference options including 1.024V, 2.048V, and 4.096V, allowing the device to optimize resolution for different signal ranges. The voltage reference selection enables applications to measure signals spanning different ranges without requiring external reference circuits or signal conditioning.

The device includes a 5-bit rail-to-rail resistive digital-to-analog converter (DAC) with positive and negative reference selection, enabling the generation of analog output signals for control applications, audio synthesis, or signal generation. The DAC output connects to the DACOUT pin, providing a programmable analog voltage output.

The analog subsystem includes two comparators with rail-to-rail inputs and outputs, enabling threshold detection and signal conditioning without requiring external comparator circuits. The comparators support software-controlled hysteresis, reducing sensitivity to noise near the comparison threshold. Power mode control allows the comparators to operate in different power consumption modes, trading off response speed against power consumption.

The voltage reference module provides fixed voltage reference outputs at 1.024V, 2.048V, and 4.096V, serving as precision references for the ADC, DAC, and comparators. These internal references eliminate the need for external reference circuits in many applications.

Digital I/O and Pin Configuration of the PIC16(L)F1936

The PIC16(L)F1936 provides 25 general-purpose I/O pins organized into five ports (RA, RB, RC, RD, and RE), plus one input-only pin. Each I/O pin supports individual programmable direction control, allowing pins to be configured as inputs or outputs under software control. The I/O pins support high-current source and sink capability, enabling direct LED drive without requiring external buffer circuits.

Each I/O pin incorporates individually programmable weak pull-up resistors, reducing the need for external pull-up components in applications using open-drain outputs or switch inputs. The pull-up resistors are disabled by default and can be selectively enabled for specific pins through software configuration.

The device includes interrupt-on-pin-change capability for selected pins, allowing the processor to wake from Sleep mode or interrupt normal execution when an I/O pin changes state. This feature enables responsive user interfaces and event-driven programming models without requiring continuous polling of input pins.

The I/O pins support multiple peripheral functions through a flexible pin assignment architecture. The Alternate Pin Function (APFCON) register allows certain peripheral functions to be reassigned to different pins, providing flexibility in board layout and accommodating different application requirements.

Serial Communication Interfaces in the PIC16(L)F1936

The PIC16(L)F1936 integrates a Master Synchronous Serial Port (MSSP) module supporting both Serial Peripheral Interface (SPI) and Inter-Integrated Circuit (I²C) protocols. The SPI interface operates in master or slave mode, supporting clock frequencies up to the device's maximum operating frequency. The SPI module includes automatic chip select handling and supports multiple slave devices on a single bus.

The I²C interface operates in master or slave mode, supporting standard I²C clock frequencies and addressing modes. The I²C module includes 7-bit address masking, enabling selective response to multiple addresses. The module supports SMBus and PMBus compatibility, allowing communication with power management and system monitoring devices.

The MSSP module incorporates auto-wake-up on I²C START condition, allowing the device to wake from Sleep mode when another master initiates I²C communication. This feature enables responsive multi-master systems without requiring continuous polling or external interrupt signals.

The Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) module provides RS-232, RS-485, and LIN-compatible serial communication. The EUSART supports standard baud rates from 300 to 1,000,000 bits per second, accommodating legacy serial devices and high-speed communication links.

The EUSART incorporates auto-baud detection, allowing the device to automatically determine the baud rate by measuring the timing of received characters. This feature simplifies system configuration and enables devices to communicate with hosts operating at unknown baud rates.

Timer and Counter Modules in the PIC16(L)F1936

The PIC16(L)F1936 provides multiple timer modules supporting various timing and counting functions. Timer0 operates as an 8-bit timer/counter with an 8-bit programmable prescaler, enabling timing intervals from microseconds to seconds depending on the prescaler setting and clock frequency.

Timer1 operates as a 16-bit timer/counter with a programmable prescaler, providing extended timing ranges compared to Timer0. Timer1 includes a dedicated low-power 32 kHz oscillator driver, enabling real-time clock applications with minimal power consumption. Timer1 supports external gate input mode with toggle and single-shot modes, enabling event counting and pulse measurement applications.

Timer1 incorporates interrupt-on-gate completion, allowing the processor to be interrupted when a gate event completes. This feature enables responsive event-driven programming without requiring continuous polling of gate status.

Timer2, Timer4, and Timer6 operate as 8-bit timer/counters with 8-bit period registers, prescalers, and postscalers. These timers support PWM time-base generation and periodic interrupt generation at programmable intervals.

Capture, Compare, and PWM Functionality in the PIC16(L)F1936

The PIC16(L)F1936 integrates five PWM modules organized as two standard Capture/Compare/PWM (CCP) modules and three Enhanced Capture/Compare/PWM (ECCP) modules. The CCP modules support 16-bit capture with maximum resolution of 125 nanoseconds, enabling precise measurement of pulse widths and timing intervals.

The CCP modules support 16-bit compare operations with maximum resolution of 125 nanoseconds, enabling precise timing of output events and pulse generation. The compare function can trigger interrupt generation or automatically toggle output pins at specified time intervals.

The CCP modules support 10-bit PWM generation with maximum frequency of 31.25 kHz, enabling motor speed control, LED brightness adjustment, and other applications requiring variable duty-cycle outputs. The PWM frequency and duty cycle are independently programmable, allowing flexible control of output characteristics.

The ECCP modules extend the standard CCP functionality with three PWM time-base options, auto-shutdown and auto-restart capability, PWM steering to multiple output pins, and programmable dead-band delay. The auto-shutdown feature automatically disables PWM outputs when a fault condition is detected, protecting against damage in motor control and power conversion applications.

The PWM steering feature allows a single PWM time-base to drive multiple output pins with different duty cycles or complementary outputs, enabling efficient implementation of three-phase motor control and other multi-output applications.

The programmable dead-band delay prevents shoot-through current in complementary output applications by introducing a controlled delay between the turn-off of one output and the turn-on of the complementary output.

LCD Display Driver Integration in the PIC16(L)F1936

The PIC16(L)F1936 integrates a dedicated LCD controller supporting up to 96 segments, enabling direct connection to LCD display panels without requiring external LCD driver circuits. The LCD controller supports variable clock input and contrast control, allowing optimization of display appearance for different viewing conditions and LCD panel characteristics.

The LCD controller provides internal voltage reference selections, eliminating the need for external reference circuits in many applications. The voltage reference options allow the LCD controller to adapt to different LCD panel requirements and operating conditions.

The LCD controller supports multiple multiplex ratios, enabling connection to LCD panels with different segment-to-common configurations. The device supports up to 1/4 multiplex displays, accommodating LCD panels with up to four common lines.

The LCD controller generates the necessary timing and voltage waveforms for LCD operation, including the AC bias voltage required to prevent LCD segment degradation. The controller automatically manages the LCD timing, reducing firmware complexity and enabling designers to focus on application functionality.

Capacitive Sensing Capabilities of the PIC16(L)F1936

The PIC16(L)F1936 integrates a capacitive sensing module (mTouch) supporting up to 16 selectable channels, enabling implementation of touch-sensitive user interfaces without requiring external sensing circuits. The capacitive sensing module measures changes in capacitance caused by finger proximity or contact, enabling responsive touch buttons and sliders.

The capacitive sensing module operates through firmware algorithms that measure the charging and discharging time of capacitive sensors connected to the device I/O pins. The module automatically compensates for environmental factors such as temperature and humidity variations, maintaining consistent touch sensitivity across operating conditions.

The capacitive sensing channels can be distributed across multiple I/O ports, allowing flexible placement of touch sensors on the device PCB. The module supports simultaneous monitoring of multiple channels, enabling multi-touch interfaces and complex touch-based control schemes.

Interrupt Handling and Context Management in the PIC16(L)F1936

The PIC16(L)F1936 provides interrupt capability with automatic context saving, enabling responsive event-driven programming without requiring manual register preservation. When an interrupt occurs, the processor automatically saves the program counter to the hardware stack, allowing the interrupt service routine to execute without corrupting the interrupted program's execution state.

The device supports multiple interrupt sources including timer overflows, serial port events, analog comparator transitions, I/O pin changes, and external interrupt inputs. Each interrupt source can be individually enabled or disabled through software configuration.

The interrupt priority system allows certain interrupts to be designated as high-priority, enabling rapid response to time-critical events. High-priority interrupts can interrupt the execution of low-priority interrupt service routines, enabling hierarchical interrupt handling for complex applications.

Code Protection and Security Features of the PIC16(L)F1936

The PIC16(L)F1936 incorporates code protection features that prevent unauthorized reading of the Flash program memory. When code protection is enabled, the device prevents external programmers from reading the contents of the Flash memory, protecting proprietary firmware from reverse engineering and intellectual property theft.

The code protection feature operates at the memory block level, allowing selective protection of different memory regions. This granular protection enables developers to protect sensitive firmware sections while allowing access to other regions for debugging or field updates.

The code protection mechanism is implemented through hardware controls that prevent memory read operations when protection is enabled. The protection persists across power cycles and device resets, maintaining security throughout the device lifetime.

Packaging and Environmental Specifications of the PIC16(L)F1936

The PIC16(L)F1936 is available in multiple package options including 28-pin SPDIP (Shrink Dual In-line Package), 28-pin SOIC (Small Outline Integrated Circuit), 28-pin SSOP (Shrink Small Outline Package), and 28-pin QFN/UQFN (Quad Flat No-lead/Ultra Quad Flat No-lead) packages. The 28-pin SOIC package measures 0.295 inches (7.50 millimeters) in width, providing a compact form factor suitable for space-constrained applications.

The device operates across an extended temperature range from -40°C to +85°C, accommodating industrial and automotive applications requiring operation in harsh environments. The device maintains specified performance across this entire temperature range, including oscillator accuracy, ADC linearity, and timing specifications.

The device is RoHS3 compliant, meeting environmental regulations restricting the use of hazardous substances in electronic products. The moisture sensitivity level is rated as MSL1 (Unlimited), indicating that the device can be stored indefinitely without moisture-related degradation.

The device is REACH compliant, meeting European Union regulations on chemical substances and their safe use. The ECCN classification is 3A991A2, and the HTSUS code is 8542.31.0001, providing information for customs and export compliance purposes.

Conclusion

The PIC16(L)F1936 represents a comprehensive solution for embedded applications requiring integrated LCD display control, extensive analog and digital I/O capabilities, and ultra-low power operation. The combination of a high-performance RISC processor, extensive peripheral integration, and power management features enables designers to implement sophisticated control systems within compact, battery-powered form factors. The device's flexible pin assignment architecture, multiple communication interfaces, and integrated LCD driver eliminate the need for external support circuits in many applications, reducing board complexity and cost. The availability of both standard and low-power voltage variants provides flexibility in power supply design, accommodating different battery technologies and operating scenarios. The comprehensive feature set and mature development ecosystem make the PIC16(L)F1936 suitable for diverse applications ranging from consumer electronics to industrial instrumentation.

Frequently Asked Questions (FAQ)

Q1. What is the maximum clock frequency supported by the PIC16(L)F1936, and how does it affect power consumption?

A1. The PIC16(L)F1936 supports clock frequencies up to 32 MHz, providing instruction cycle times as fast as 125 nanoseconds. Higher clock frequencies enable faster instruction execution and improved real-time responsiveness but increase power consumption proportionally. At 1 MHz and 1.8V, the PIC16LF1936 consumes approximately 150 microamperes, while at 32 kHz operation, consumption drops to approximately 7.0 microamperes. Designers can select the appropriate clock frequency based on their performance requirements and power budget.

Q2. How many I/O pins does the PIC16(L)F1936 provide, and what are their current-driving capabilities?

A2. The PIC16(L)F1936 provides 25 general-purpose I/O pins organized into five ports (RA, RB, RC, RD, and RE), plus one input-only pin. The I/O pins support high-current source and sink capability, enabling direct LED drive without requiring external buffer circuits. Each pin can be individually configured as an input or output, and selected pins support weak pull-up resistors and interrupt-on-change functionality.

Q3. What memory capacity does the PIC16(L)F1936 provide for program storage and data retention?

A3. The PIC16(L)F1936 integrates 8192 words (14 kilobytes) of Flash program memory for application firmware, 256 bytes of EEPROM for non-volatile data storage, and 512 bytes of SRAM for runtime variables. The Flash memory supports 100,000 write cycles per location with retention exceeding 40 years, while the EEPROM supports 1,000,000 write cycles per byte with identical retention specifications.

Q4. How does the PIC16(L)F1936 achieve such low standby current consumption, and what applications benefit from this capability?

A4. The PIC16(L)F1936 achieves standby current as low as 60 nanoamperes at 1.8V through Microchip's nanoWatt XLP power management architecture, which minimizes leakage current and provides efficient Sleep mode operation. This ultra-low standby current enables battery-powered applications such as wireless sensors, portable medical devices, and energy meters to operate for extended periods on small coin-cell batteries while maintaining real-time clock functionality and responsiveness to external events.

Q5. What serial communication protocols does the PIC16(L)F1936 support, and how are they implemented?

A5. The PIC16(L)F1936 supports SPI, I²C, RS-232, RS-485, and LIN communication protocols through integrated MSSP and EUSART modules. The MSSP module handles SPI and I²C communication with support for multiple addressing modes and automatic chip select handling. The EUSART module provides RS-232, RS-485, and LIN compatibility with auto-baud detection capability, enabling communication with devices operating at unknown baud rates.

Q6. What is the maximum number of LCD segments the PIC16(L)F1936 can drive, and what external components are required?

A6. The PIC16(L)F1936 integrates an LCD controller supporting up to 96 segments with variable clock input and contrast control. The LCD controller generates the necessary timing and voltage waveforms for LCD operation, including the AC bias voltage required to prevent LCD segment degradation. In many applications, no external LCD driver circuits are required, as the integrated controller provides direct connection to LCD display panels.

Q7. How does the capacitive sensing module (mTouch) function, and what types of user interfaces can be implemented?

A7. The capacitive sensing module supports up to 16 selectable channels that measure changes in capacitance caused by finger proximity or contact. The module operates through firmware algorithms that measure the charging and discharging time of capacitive sensors connected to I/O pins, with automatic compensation for environmental factors such as temperature and humidity. This enables implementation of touch-sensitive buttons, sliders, and other touch-based user interfaces without requiring external sensing circuits.

Q8. What are the differences between the PIC16F1936 and PIC16LF1936 variants, and how should designers choose between them?

A8. The PIC16F1936 operates across 1.8V to 5.5V supply voltage, while the PIC16LF1936 is optimized for 1.8V to 3.6V operation. Both variants share identical instruction sets and peripheral configurations. Designers should select the PIC16F1936 for applications using higher supply voltages or requiring operation across a wider voltage range, and the PIC16LF1936 for battery-powered applications where supply voltage remains below 3.6V.

Q9. What code protection mechanisms does the PIC16(L)F1936 provide, and how effective are they against reverse engineering?

A9. The PIC16(L)F1936 incorporates code protection features that prevent unauthorized reading of the Flash program memory through external programmers. The protection operates at the memory block level, allowing selective protection of different memory regions. When enabled, the protection persists across power cycles and device resets. However, code protection does not guarantee absolute security against all attack methods, and designers should implement additional security measures for applications requiring the highest levels of intellectual property protection.

Q10. What are the typical applications for the PIC16(L)F1936, and what advantages does it offer compared to general-purpose microcontrollers?

A10. The PIC16(L)F1936 is well-suited for battery-powered consumer electronics, industrial instrumentation, portable medical devices, wireless sensors, and energy meters. The integrated LCD driver eliminates the need for external display driver circuits, reducing board complexity and cost. The ultra-low power consumption enables extended battery runtime, while the extensive peripheral integration reduces the need for external support circuits. The high-performance RISC processor and comprehensive instruction set enable implementation of sophisticated control algorithms within the compact 28-pin package.

Q11. How does the Brown-out Reset (BOR) function protect against power supply transients, and what are the selectable trip points?

A11. The Brown-out Reset circuit monitors the supply voltage and forces a device reset if the voltage drops below a selectable threshold, protecting against data corruption and erratic behavior during power supply transients. The device provides two selectable trip points, allowing designers to choose the reset threshold appropriate for their specific power supply architecture and application requirements. This prevents the processor from executing instructions with insufficient supply voltage, which could cause memory corruption or unpredictable behavior.

Q12. What PWM capabilities does the PIC16(L)F1936 provide, and how can they be used in motor control applications?

A12. The PIC16(L)F1936 provides two standard CCP modules and three ECCP modules supporting 10-bit PWM generation with maximum frequency of 31.25 kHz. The ECCP modules include auto-shutdown and auto-restart capability, PWM steering to multiple output pins, and programmable dead-band delay. These features enable efficient implementation of motor speed control, LED brightness adjustment, and three-phase motor control applications. The auto-shutdown feature protects against damage by automatically disabling PWM outputs when a fault condition is detected.

Q13. How does the precision internal oscillator maintain accuracy, and what frequency range does it support?

A13. The precision internal oscillator is factory calibrated to ±1% accuracy and supports a software-selectable frequency range from 31 kHz to 32 MHz. The internal oscillator eliminates the need for external crystal components in many applications, reducing board space and component cost. The dedicated low-power 32 kHz oscillator driver consumes approximately 600 nanoamperes at 1.8V, enabling real-time clock applications with minimal power consumption.

Q14. What interrupt sources are available on the PIC16(L)F1936, and how does the interrupt priority system function?

A14. The PIC16(L)F1936 supports multiple interrupt sources including timer overflows, serial port events, analog comparator transitions, I/O pin changes, and external interrupt inputs. Each interrupt source can be individually enabled or disabled through software configuration. The interrupt priority system allows certain interrupts to be designated as high-priority, enabling rapid response to time-critical events. High-priority interrupts can interrupt the execution of low-priority interrupt service routines, enabling hierarchical interrupt handling for complex applications.

Q15. What are the temperature operating range and environmental compliance specifications for the PIC16(L)F1936?

A15. The PIC16(L)F1936 operates across an extended temperature range from -40°C to +85°C, accommodating industrial and automotive applications requiring operation in harsh environments. The device maintains specified performance across this entire temperature range, including oscillator accuracy, ADC linearity, and timing specifications. The device is RoHS3 compliant and REACH compliant, meeting environmental regulations restricting hazardous substances. The moisture sensitivity level is rated as MSL1 (Unlimited), indicating unlimited storage life without moisture-related degradation.