MC68HC908EY16 Datasheet, PDF (209/278 Pages) Motorola, Inc – Microcontrollers

Chapter 18
Timer Interface B (TIMB) Module
18.1 Introduction
This section describes the timer interface B module (TIMB). The TIMB is a 2-channel timer that provides
a timing reference with input capture, output compare, and pulse width modulation (PWM) functions.
Figure 18-2 is a block diagram of the TIMB.
For further information regarding timers on M68HC08 family devices, please consult the HC08 Timer
Reference Manual, Freescale document order number TIM08RM/AD.
18.2 Features
Features include:
• Two input capture/output compare channels
– Rising-edge, falling-edge, or any-edge input capture trigger
– Set, clear, or toggle output compare action
• Buffered and unbuffered PWM signal generation
• Programmable TIMB clock input
– 7-frequency internal bus clock prescaler selection
• Free-running or modulo up-count operation
• Toggle any channel pin on overflow
• TIMB counter stop and reset bits
18.3 Functional Description
Figure 18-2 shows the TIMB structure. The central component of the TIMB is the 16-bit TIMB counter that
can operate as a free-running counter or a modulo up-counter. The TIMB counter provides the timing
reference for the input capture and output compare functions. The TIMB counter modulo registers,
TBMODH–TBMODL, control the modulo value of the TIMB counter. Software can read the TIMB counter
value at any time without affecting the counting sequence.
The two TIMB channels are programmable independently as input capture or output compare channels.
MC68HC908EY16 • MC68HC908EY8 Data Sheet, Rev. 10
Freescale Semiconductor
209