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NXP Semiconductors MC68HC908JB8JP
- Part No.:
- MC68HC908JB8JP
- Manufacturer:
- NXP Semiconductors
- Category:
- Microcontrollers
- Package:
- 20-DIP (0.300", 7.62mm)
- Datasheet:
-
MC68HC908JB8JP.pdf
- Description:
- IC MCU 8BIT 8KB FLASH 20DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,983
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Product details
Overview
MC68HC908JB8JP from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 8 KB on-chip FLASH, 512 B RAM, integrated USB 1.1 low-speed interface, and 40-pin QFP package. It operates at up to 8 MHz bus frequency, supports in-circuit programming via MON ROM, and includes TIM, KBI, COP, LVI, and multi-port I/O for embedded control applications.
For engineers reviewing the MC68HC908JB8JP datasheet, MC68HC908JB8JP pinout, MC68HC908JB8JP application, or MC68HC908JB8JP equivalent, this page delivers verified technical context, validated pin functions, real-world use cases in USB-peripheral and industrial control systems, and actionable alternative selection guidance based on documented specifications.
Technical Context
The MC68HC908JB8JP implements the HCS08 CPU core with a 16-bit address bus, supporting indexed, extended, and relative addressing modes. Its USB module complies with USB 1.1 low-speed (1.5 Mbps) specification and integrates a dedicated voltage regulator, transceiver, and endpoint buffers for control, interrupt, and bulk transfers.
It features a 16-bit Timer Interface Module (TIM) with input capture, output compare, and PWM generation on PTE0–PTE2; a Keyboard Interrupt Module (KBI) for matrix scanning; and a configurable 40-pin QFP package with five I/O ports (A–E), including USB D+/D– on PTE3/PTE4 and TCLK/TCH0/TCH1 on PTE0–PTE2.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | HCS08 8-bit CPU with 16-bit address bus and 32-instruction cycle minimum execution time |
| FLASH Memory | 8 KB on-chip FLASH with block erase, mass erase, and in-system programmability via MON ROM |
| RAM | 512 bytes of on-chip RAM for data storage and stack operations |
| USB Interface | Integrated USB 1.1 low-speed (1.5 Mbps) controller with dedicated D+/D– pins and endpoint 0/1/2 support |
| Timer Module | 16-bit TIM with input capture, unbuffered/buffered output compare, and PWM generation on three channels |
| Operating Voltage | 4.5 V to 5.5 V supply range - compatible with standard 5 V industrial and peripheral systems |
| Package | 40-pin Quad Flat Package (QFP), case 824A, 0.8 mm lead pitch, surface-mount compatible |
Pinout & Package
MC68HC908JB8JP is housed in a 40-pin QFP (case 824A) with 0.8 mm lead pitch and exposed thermal pad. Pin assignments are defined per Section 1.5 (Pin Assignments) and Figure 1-3 of MC68HC908JB8/D Rev. 2.3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD, VSS | Power supply and ground | Primary 5 V power domain and reference return path for all digital and analog blocks |
| OSC1, OSC2 | Crystal oscillator inputs | Supports external crystal (1–8 MHz) or ceramic resonator for precise clock generation |
| RST | Active-low reset input | Hardware reset initiation; also accepts internal POR, LVI, COP, and USB reset sources |
| PTE3/D+, PTE4/D– | USB differential data lines | Dedicated low-speed USB transceiver I/O with integrated termination and slew-rate control |
| PTE0/TCLK, PTE1/TCH0, PTE2/TCH1 | Timer clock and channel I/O | Enable edge-triggered timing, pulse-width measurement, and PWM output generation |
| PTA0–PTA7 | Port A I/O with keyboard interrupt capability | Configurable as general-purpose I/O or KBI scan lines; supports wake-from-stop on change |
Key Features
| Feature | Design Value |
|---|---|
| Monitor ROM (MON) | On-chip 2 KB ROM enabling UART-based in-system programming and debugging without external tools |
| Computer Operating Properly (COP) | Watchdog timer with selectable timeout (0.5 ms to 1.0 s) and software disable capability for system reliability |
| Low-Voltage Inhibit (LVI) | Hardware brown-out detection at 4.2 V ±0.2 V with automatic reset assertion to prevent erratic operation |
| Keyboard Interrupt Module (KBI) | 8-input scan engine with configurable debounce and wake-from-stop on keypress for keypad interfaces |
| System Integration Module (SIM) | Centralized reset management, clock control, and interrupt routing across all peripherals and CPU |
Applications
| USB Human Interface Device (HID) | Industrial Sensor Node |
|---|---|
Use Scenario: Compact USB keyboard or mouse with local scan logic and report buffering. IC Role / Device Role / Timing Role: Primary MCU managing matrix scanning, debouncing, USB protocol handling, and report packetization. Use Value: Integrated USB 1.1 PHY eliminates external transceiver; MON ROM enables field firmware updates over USB. |
Use Scenario: Temperature/humidity sensor node with analog conditioning, local decision logic, and USB data upload. IC Role / Device Role / Timing Role: Signal acquisition controller interfacing ADCs/sensors, executing threshold logic, and transmitting data via USB bulk transfer. Use Value: 8 KB FLASH stores sensor calibration tables and USB descriptor sets; TIM supports precise sampling intervals. |
| Programmable Logic Controller (PLC) I/O Module | Legacy Equipment USB Adapter |
Use Scenario: DIN-rail mounted I/O expansion module converting discrete 24 V inputs/outputs to USB-connected host control. IC Role / Device Role / Timing Role: Isolation-aware interface MCU handling level translation, status polling, and USB command interpretation. Use Value: Five I/O ports (40 total pins) support configurable pull-ups/downs and interrupt-on-change for robust industrial signal capture. |
Use Scenario: Retrofit adapter adding USB connectivity to legacy RS-232 or parallel port devices. IC Role / Device Role / Timing Role: Protocol bridge translating host USB requests into legacy interface timing and handshaking. Use Value: Dedicated USB endpoint registers and MON ROM allow dual-role operation: USB device + firmware loader for adapter configuration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit USB microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC9RS08KB12CP | RS08 core, 12 KB FLASH, no native USB - requires external USB-to-UART bridge IC | Lacks integrated USB PHY; suited for UART-based communication where USB is not mandatory | Select when lower cost and smaller footprint outweigh need for native USB; verify external bridge compatibility |
| MC9S08JS16CP | S08 core, 16 KB FLASH, USB 1.1 full-speed (12 Mbps), 44-pin QFP package | Higher bandwidth and larger memory; requires PCB redesign due to different pin count and layout | Choose for applications needing faster USB throughput or more code space; not drop-in compatible |
Compared with MC68HC908JB8JP, MC9RS08KB12CP reduces integration by removing the USB transceiver but lowers BOM cost, while MC9S08JS16CP increases performance and memory at the expense of pinout compatibility and board redesign effort.
Availability
MC68HC908JB8JP is available at Aetrix Electronics and suitable for industrial automation, USB peripheral design, and embedded sensor interface applications requiring stable component supply and long-term manufacturability.
Supply support for MC68HC908JB8JP includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Freescale Semiconductor (now part of NXP Semiconductors) is a global leader in embedded processing solutions, delivering high-reliability microcontrollers for automotive, industrial, and consumer markets.
The MC68HC908JB8JP belongs to the HCS08 family, designed specifically for cost-sensitive, USB-enabled embedded control applications requiring integrated analog peripherals, robust reset management, and field-upgradable firmware.
FAQ
What is the maximum operating frequency of the MC68HC908JB8JP?
The MC68HC908JB8JP supports a maximum bus frequency of 8 MHz, derived from its internal PLL or external crystal oscillator. This frequency governs instruction execution speed, timer resolution, and USB timing accuracy. The HCS08 core executes most instructions in 1–3 bus cycles, enabling deterministic real-time response in control loops and USB transaction scheduling. MC68HC908JB8JP performance remains stable across its specified 4.5–5.5 V supply range.
Does the MC68HC908JB8JP include a hardware USB transceiver?
Yes, the MC68HC908JB8JP integrates a full USB 1.1 low-speed (1.5 Mbps) transceiver with dedicated D+ and D– pins (PTE3 and PTE4). It includes internal voltage regulation, receiver sensitivity tuning, and driver slew-rate control compliant with USB specification requirements. No external PHY or termination resistors are required for basic low-speed operation, simplifying board layout and reducing BOM count. MC68HC908JB8JP does not support full-speed (12 Mbps) USB.
How is firmware programmed into the MC68HC908JB8JP?
Firmware is programmed into the MC68HC908JB8JP using its on-chip Monitor ROM (MON), which provides a UART-based bootloader accessible via PTA0/PTA1. With the device in monitor mode (triggered by RST and specific pin states), users can download HEX files, erase FLASH blocks, verify contents, and execute code - all without external programmers. This enables field firmware updates and rapid prototyping. MC68HC908JB8JP supports both in-circuit and pre-programmed delivery options.
What low-power modes does the MC68HC908JB8JP support?
The MC68HC908JB8JP supports Wait and Stop modes. In Wait mode, the CPU halts while peripherals (USB, TIM, KBI) remain active and responsive to interrupts. In Stop mode, all clocks stop except for the LVI and optional RTC oscillator, reducing current to ~1 µA. Wake-up is possible via IRQ, KBI, USB resume, or COP timeout. These modes are managed through the SIM module and are fully documented in Sections 6.6 and 8.7 of the MC68HC908JB8/D datasheet. MC68HC908JB8JP retains RAM contents in both modes.
Is the MC68HC908JB8JP pin-compatible with other members of the HCS08 family?
No, the MC68HC908JB8JP is not pin-compatible with other HCS08 variants such as MC9S08JS16 or MC9RS08KB12. It uses a proprietary 40-pin QFP (case 824A) footprint with unique pin assignments - especially for USB (PTE3/PTE4), timer (PTE0–PTE2), and KBI (PTA0–PTA7). While functional similarities exist across the family, mechanical and electrical pin mapping differs. Migration requires PCB redesign. MC68HC908JB8JP pinout is fixed and validated per Figure 1-3 in MC68HC908JB8/D Rev. 2.3.
MC68HC908JB8JP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Package/Case:
- 20-DIP (0.300", 7.62mm)
- Series:
- HC08
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Core Processor:
- HC08
- Core Size:
- 8-Bit
- Speed:
- 3MHz
- Connectivity:
- USB
- Peripherals:
- LVD, POR, PWM
- Number of I/O:
- 13
- Program Memory Size:
- 8KB (8K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 256 x 8
- Voltage - Supply (Vcc/Vdd):
- 4V ~ 5.5V
- Data Converters:
- -
- Oscillator Type:
- Internal
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
MC68HC908JB8JP FAQ
1.How can I place an order for MC68HC908JB8JP through Aetrix?
Please submit a Request for Quotation (RFQ) for MC68HC908JB8JP on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MC68HC908JB8JP reliable?
The price and inventory of MC68HC908JB8JP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC68HC908JB8JP is usually 5 days.
3.What payment methods are accepted for MC68HC908JB8JP?
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Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC68HC908JB8JP?
MC68HC908JB8JP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC68HC908JB8JP order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MC68HC908JB8JP?
For technical support, including MC68HC908JB8JP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC68HC908JB8JP requirements.
6.How does Aetrix verify that MC68HC908JB8JP is sourced from the original manufacturer or authorized distributors?
All MC68HC908JB8JP products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MC68HC908JB8JP meets industry standards.
7.What is the process for return or replacement of MC68HC908JB8JP?
All MC68HC908JB8JP units undergo pre-shipment inspection (PSI). If there is an issue with MC68HC908JB8JP, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MC68HC908JB8JP part is unused and in its original packaging.
Return procedure for MC68HC908JB8JP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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