Описание
The MC68HC908GR4 is a device identical to the MC68HC908GR8 except that it has less Flash memory. Only when the MC68HC908GR4 specifically mentioned in the text.
- High-performance M68HC08 architecture optimized for C-compilers
 - Fully upward-compatible object code with M6805, M146805, and M68HC05 Families
 - 8-MHz internal bus frequency
 - FLASH program memory security(1)
 - On-chip programming firmware for use with host personal computer which does not require high voltage for entry
 - In-system programming
 - System protection features:
- Optional computer operating properly (COP) reset
 - Low-voltage detection with optional reset and selectable trip points for 3.0 V and 5.0 V operation
 - Illegal opcode detection with reset
 - Illegal address detection with reset
 
 - Low-power design; fully static with stop and wait modes
 - Standard low-power modes of operation: -Wait mode
- Stop mode
 
 - Master reset pin and power-on reset (POR)
 - The MC68HC908GR4 with in-circuit programming capabilities of FLASH program memory
 - 384 bytes of on-chip random-access memory (RAM)
 - Serial peripheral interface module (SPI)
 - Serial communications interface module (SCI)
 - One 16-bit, 2-channel timer (TIM1) and one 16-bit, 1-channel timer (TIM2) interface modules with selectable input capture, output compare, and PWM capability on each channel
 - 6-channel, 8-bit successive approximation analog-to-digital converter (ADC)
 - BREAK module (BRK) to allow single breakpoint setting during in-circuit debugging
 - Internal pullups on IRQ and RST to reduce customer system cost
 - Clock generator module with on-chip 32-kHz crystal compatible PLL (phase-lock loop)
 - Up to 21 general-purpose input/output (I/O) pins, including:
- 19 shared-function I/O pins
 - Up to two dedicated I/O pins, depending on package choice
 
 - Selectable pullups on inputs only on ports A, C, and D. Selection is on an individual port bit basis. During output mode, pullups are disengaged.
 - High current 10-mA sink/10-mA source capability on all port pins
 - Higher current 15-mA sink/source capability on PTC0–PTC1
 - Timebase module with clock prescaler circuitry for eight user selectable periodic real-time interrupts with optional active clock source during stop mode for periodic wakeup from stop using an external 32-kHz crystal
 - Oscillator stop mode enable bit (OSCSTOPENB) in the CONFIG register to allow user selection of having the oscillator enabled or disabled during stop mode
 - 4-bit keyboard wakeup port
 - 42-pin shrink dual in-line package (SDIP), 32-pin quad flat pack (QFP), 28-pin plastic dual-in-line package (DIP), or 28-pin small outline integrated circuit (SOIC)
 
