Introduction

The MC68HC908MR8 is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCU). The M68HC08 Family is based on the customer-specified integrated circuit (CSIC) design strategy. All MCUs in the family use the enhanced M68HC08 central processor unit (CPU08) and are available with a variety of modules, memory sizes and types, and package types.

Features

Features of the MC68HC908MR8 include:

• High-performance M68HC08 architecture

• Fully upward-compatible object code with M6805, M146805, and

M68HC05 Families

• 8-MHz internal bus frequency

• 8 Kbytes of on-chip FLASH

• On-chip programming firmware for use with host personal

computer

• 256 bytes of on-chip random-access memory (RAM):

• 12-bit, 6-channel center-aligned or edge-aligned pulse-width

modulator (PWMMC)

• Serial communications interface module (SCI)

• Two 16-bit, 2-channel timer interface modules (TIMA and TIMB)

• Eight high current sink and source pins (PTA1/ATD1, PTA0/ATD0,

PTB6/TCH1B, PTB5/TCH0B, PTB4/TCH1A, PTB3/TCH0A,

PTB2/TCLKA, and PTB1/TxD)

• Clock generator module (CGM)

• Digitally filtered low-voltage inhibit (LVI), software selectable for

±5 percent or ±10 percent tolerance

• 10-bit, 4 to 7-channel analog-to-digital converter (ADC)

• System protection features:

– Optional computer operating properly (COP) reset

– Low-voltage detection with optional reset

– Illegal opcode detection with optional reset

– Illegal address detection with optional reset

– Fault detection with optional PWM disabling

• Available packages:

– 32-pin low-profile quad flat pack (LQFP)

– 28-pin dual in-line package (PDIP)

– 28-pin small outline package (SOIC)

• Low-power design, fully static with stop and wait modes

• Break (BRK) module allows single breakpoint setting during

in-circuit debugging

• Master reset pin and power-on reset (POR)

Features of the CPU08 include:

• Enhanced HC05 programming model

• Extensive loop control functions

• 16 addressing modes (eight more than the M68HC05)

• 16-bit index register and stack pointer

• Memory-to-memory data transfers

• Fast 8 × 8 multiply instruction

• Fast 16 ÷ 8 divide instruction

• Binary-coded decimal (BCD) instructions

• Optimization for controller applications

• C language support