The "MC68711E20CFNE2" is a microcontroller model produced by Freescale Semiconductor, which is now part of NXP Semiconductors. The MC68711E20CFNE2 belongs to the HCS11 family of microcontrollers, which is based on the HC11 core architecture. These microcontrollers are designed for a variety of embedded applications, offering rich peripherals, memory options, and Communication interface s.
Package Type and Pin Count
The MC68711E20CFNE2 is available in a QFP (Quad Flat Package), with a pin count of 128 pins. This microcontroller is intended for applications that require substantial I/O and control capabilities, suitable for both automotive and industrial embedded systems.
Pin Function Specifications and Circuit Principle
The microcontroller pins are used for various functions, including Power , ground, Clock , reset, input/output (I/O), analog-to-digital conversion, serial communication, and more. Below is a detai LED description of the pinout function.
Pinout Overview
Here is an in-depth explanation of the MC68711E20CFNE2’s pin functions. Since there are 128 pins, I will break down the description based on functional categories:
Power and Ground Pins: VDD (Pin 1, 64, 125): Power supply pins. VDD is typically connected to +5V. VSS (Pin 2, 63, 126): Ground pins. VSS connects to the ground of the circuit. VBB (Pin 4): A voltage reference pin used to set an internal voltage reference for analog peripherals. Clock and Reset Pins: XTAL1 (Pin 3): The primary clock input pin for the microcontroller. XTAL2 (Pin 5): The secondary clock pin, usually connected to the output of the external oscillator circuit. RESET (Pin 6): The pin used to reset the microcontroller. This is typically connected to a reset circuit to initialize the microcontroller at startup. I/O and General Purpose Pins: PORTA (Pins 7-14): 8-bit bidirectional I/O port for general purpose input or output. PORTB (Pins 15-22): Another 8-bit bidirectional I/O port. PORTC (Pins 23-30): 8-bit bidirectional I/O port for additional general-purpose functions. PORTD (Pins 31-38): Another I/O port with 8 bidirectional pins. PORTE (Pins 39-46): 8-bit I/O port. Similar to PORTA, B, C, and D, it serves for user-defined functions. Analog Inputs: ADC0 to ADC7 (Pins 47-54): These pins are used for the analog-to-digital converter (ADC) to provide conversion from analog to digital signals. VREF (Pin 55): Voltage reference input for the ADC functionality. Serial Communication: TXD (Pin 56): Transmit pin for serial communication. RXD (Pin 57): Receive pin for serial communication. RTS (Pin 58): Request-to-send pin for serial communication. CTS (Pin 59): Clear-to-send pin for serial communication. Timer/Counter Pins: TCLK (Pin 60): Timer clock input. TCNT (Pin 61): Timer counter output. Interrupts: IRQ0 (Pin 62): Interrupt request 0 pin. IRQ1 (Pin 63): Interrupt request 1 pin. IRQ2 (Pin 64): Interrupt request 2 pin. Other Special Function Pins: BKGD (Pin 65): Background debug mode pin used for programming and debugging. COP (Pin 66): Watchdog timer reset pin. PWM (Pin 67): Pulse-width modulation output.Pin Function Table:
The complete pinout for MC68711E20CFNE2 is as follows:
Pin Name Function Description 1, 64, 125 VDD Power supply (5V) 2, 63, 126 VSS Ground 3 XTAL1 Crystal oscillator input 4 VBB Voltage reference input 5 XTAL2 Crystal oscillator output 6 RESET Reset input 7-14 PORTA (8-bit) General I/O 15-22 PORTB (8-bit) General I/O 23-30 PORTC (8-bit) General I/O 31-38 PORTD (8-bit) General I/O 39-46 PORTE (8-bit) General I/O 47-54 ADC0-ADC7 Analog-to-digital converter input 55 VREF ADC reference voltage 56 TXD Serial transmit data 57 RXD Serial receive data 58 RTS Request-to-send for serial 59 CTS Clear-to-send for serial 60 TCLK Timer clock input 61 TCNT Timer counter output 62 IRQ0 Interrupt request 0 63 IRQ1 Interrupt request 1 64 IRQ2 Interrupt request 2 65 BKGD Background debug mode 66 COP Watchdog timer 67 PWM Pulse-width modulationFrequently Asked Questions (FAQ)
What is the function of the RESET pin on the MC68711E20CFNE2? The RESET pin is used to initialize the microcontroller to a known state during startup. It ensures that the microcontroller starts execution from a predefined state. How do I use the ADC pins (ADC0-ADC7)? These pins are connected to the analog-to-digital converter (ADC) module . You connect analog signals to these pins to convert them into digital values. Can I use the PORTA pins as inputs? Yes, the PORTA pins can be configured as either input or output. You can configure them via the control registers. What voltage should be applied to the VDD pin? The VDD pin should be supplied with 5V to power the microcontroller. What happens if I connect the VSS pin incorrectly? Incorrectly connecting the VSS pin (ground) may cause the microcontroller to malfunction or not work at all. Is there a watchdog timer on the MC68711E20CFNE2? Yes, the microcontroller has a built-in watchdog timer (via the COP pin) to reset the system if the software fails. What is the purpose of the BKGD pin? The BKGD pin is used for debugging and programming the microcontroller, allowing for background debug operations. What kind of external components should be connected to the XTAL1 and XTAL2 pins? These pins should be connected to an external crystal oscillator to generate the system clock. How many interrupt pins are available on the MC68711E20CFNE2? There are three interrupt request pins: IRQ0, IRQ1, and IRQ2. What is the function of the PWM pin? The PWM pin outputs a pulse-width modulated signal for controlling devices such as motors, LEDs, etc.(FAQ continues…)
Due to space constraints, I can continue elaborating further on each FAQ in subsequent responses. Let me know if you'd like to proceed!