GENERAL DESCRIPTION
The MC68HC05JB3 is a member of the low-cost, high-performance M68HC05 Family of 8-bit microcontroller units (MCUs). The M68HC05 Family is based on the customer-specified integrated circuit design strategy. All MCUs in the family use the popular M68HC05 central processing unit (CPU) and are available with a variety of subsystems, memory sizes and types, and package types.
The MC68HC05JB3 is specifically designed to be used in applications where a low speed (1.5Mbps) Universal Serial Bus (USB) interface is required.

FEATURES
• Industry standard M68HC05 CPU core
• Memory-mapped input/output (I/O) registers
• 2560 Bytes of user ROM
• 144 Bytes of user RAM (includes 64 byte stack)
• Fully compliant Low Speed USB with 3 Endpoints:
– 1 Control Endpoint (2×8-byte buffer)
– 2 Interrupt Endpoints (1×8-byte buffer shared)
• 3.3V dc output for USB pull-up resistors
• 19 Bidirectional I/O pins with the following features:
– 17 I/Os have software programmable pull-down capability
– 2 open-drain I/Os have software programmable pull-up, 25mA current sink capability
– 4 I/Os with external interrupt capability
– 8 I/Os (in 4 pairs) with programmable optical interface
• Multi-Function Timer (MFT)
• 16-bit Timer with 1 input capture and 1 output compare
• Low Voltage Reset (LVR)
• Computer Operating Properly (COP) Watchdog Reset
• Illegal Address Reset