MC68HC705J1ACDW

The MC68HC705J1ACDW is an 8‑bit microcontroller from the Freescale/NXP 68HC05 family. It combines a CPU, on‑chip memory, and peripherals in a small, low‑cost device for embedded control.
- Core: 8‑bit processor compatible with the 6800/68HC05 instruction set, designed for simple, low‑power control tasks.
- Memory: On‑chip ROM and RAM (sizes are device‑variant specific; check the datasheet for exact figures).
- Peripherals: Common HC05 peripherals such as a serial communications interface (SCI), timers, watchdog timer, general‑purpose I/O, and reset/clock options.
- Package/variant: The “ACDW” suffix identifies the specific package and temperature/grade option for this part; exact pin count and package type are in the datasheet.
- Use cases: Small appliances, automotive body controllers, and other cost‑sensitive embedded applications requiring compact hardware.
- Development: Program in assembly or C with standard 68HC05 toolchains; refer to the user guide for development, debugging, and programming details.
For precise memory sizes, pin count, and features, consult the MC68HC705J1ACDW datasheet and reference manuals.

Key features of MC68HC705J1ACDW (HC05 family, 28-pin package):
- 8-bit HC05 CPU core with 16-bit address space
- On-chip program memory (ROM/Flash) and RAM
- Multiple I/O lines and ports for GPIO
- Serial communications interface (SCI) for asynchronous serial I/O
- Timers: at least one 8-bit timer; watchdog timer
- Interrupt system with vectored, prioritized interrupts
- Low-power operation and sleep/idle modes
- Operating voltage typically 2.7–5.5 V
- External clock/crystal input (clock source) and modest clock rates
- In-system programmable memory (flash) for firmware updates
- 28-pin package variants (DIP/SOIC) compatible with standard MCU designs
Note: Peripherals can vary by exact device variant within the HC705J1 family; consult the datasheet for exact RAM/ROM sizes and peripheral set for MC68HC705J1ACDW.

Plastic DIP, 20-pin (DIP-20) package.

- Pin count: 28 pins
- Function: 8-bit microcontroller in the 68HC05 family (MC68HC705J1A) with on-chip ROM and RAM, I/O ports, timers, and a serial interface for embedded control applications.

- Manufacturer: Freescale Semiconductor (now part of NXP Semiconductors).
- What kind of company: A global semiconductor company that designs and manufactures embedded processing ICs, especially microcontrollers; originally spun off from Motorola’s semiconductor division and later acquired by NXP.

Typical applications include automotive body electronics, consumer electronics, home appliances, and small industrial control/instrumentation systems. It is suited for low-cost, low-power embedded control tasks such as sensor interfacing, keypad control, timing, basic motor control, and simple communication.