Datasheet

MC68HC908QB8 Data Sheet, Rev. 3
Freescale Semiconductor 17
Chapter 1
General Description
1.1 Introduction
The MC68HC908QB8 is a member of the low-cost, high-performance M68HC08 Family of 8-bit
microcontroller units (MCUs). 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.
0.4
1.2 Features
Features include:
• High-performance M68HC08 CPU core
• Fully upward-compatible object code with M68HC05 Family
• 5-V and 3-V operating voltages (V
DD
)
• 8-MHz internal bus operation at 5 V, 4-MHz at 3 V
• Trimmable internal oscillator
– Software selectable 1 MHz, 2 MHz, or 3.2 MHz internal bus operation
– 8-bit trim capability
– ± 25% untrimmed
– Trimmable to approximately 0.4%
(1)
• Software selectable crystal oscillator range, 32–100 kHz, 1–8 MHz, and 8–32 MHz
• Software configurable input clock from either internal or external source
• Auto wakeup from STOP capability using dedicated internal 32-kHz RC or bus clock source
• On-chip in-application programmable FLASH memory
– Internal program/erase voltage generation
– Monitor ROM containing user callable program/erase routines
– FLASH security
(2)
Table 1-1. Summary of Device Variations
Device
FLASH/RAM
Memory Size
ADC
16-Bit Timer
Channels
ESCI SPI
Pin
Count
MC68HC908QB8 8K/256 bytes 10 channel, 10 bit 4 Yes Yes 16 pins
MC68HC908QB4 4K/128 bytes 10 channel, 10 bit 4 Yes Yes 16 pins
MC68HC908QY8 8K/256 bytes 4 channel, 10 bit 2 No No 16 pins
1. See 18.11 Oscillator Characteristics for internal oscillator specifications
2. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the FLASH difficult for
unauthorized users.