MC68HC908GP20 Datasheet, PDF (345/406 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Advance Information — MC68HC908GP20
Section 21. Timebase Module (TBM)
21.1 Contents
21.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345
21.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345
21.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .346
21.5 Timebase Register Description. . . . . . . . . . . . . . . . . . . . . . . . 347
21.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .348
21.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
21.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
21.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
21.2 Introduction
This section describes the timebase module (TBM). The TBM will
generate periodic interrupts at user selectable rates using a counter
clocked by the external crystal clock. This TBM version uses 15 divider
stages, eight of which are user selectable.
21.3 Features
Features of the TBM module include:
• Software programmable 1-Hz, 4-Hz, 16-Hz, 256-Hz, 512-Hz,
1024-Hz, 2048-Hz, and 4096-Hz periodic interrupt using external
32.768-kHz crystal
• User selectable oscillator clock source enable during stop mode to
allow periodic wakeup from stop
MC68HC908GP20 — Rev 2.1
Freescale Semiconductor
Advance Information
345