MC68HC908EY16 Datasheet, PDF (193/278 Pages) Motorola, Inc – Microcontrollers

Chapter 17
Timer Interface A (TIMA) Module
17.1 Introduction
This section describes the timer interface A module (TIMA). The TIMA is a 2-channel timer that provides
a timing reference with input capture, output compare, and pulse width modulation (PWM) functions.
Figure 17-2 is a block diagram of the TIMA.
For further information regarding timers on M68HC08 family devices, please consult the HC08 Timer
Reference Manual, Freescale document order number TIM08RM/AD.
17.2 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 TIMA clock input
– 7-frequency internal bus clock prescaler selection
• Free-running or modulo up-count operation
• Toggle any channel pin on overflow
• TIMA counter stop and reset bits
17.3 Functional Description
Figure 17-2 shows the TIMA structure. The central component of the TIMA is the 16-bit TIMA counter that
can operate as a free-running counter or a modulo up-counter. The TIMA counter provides the timing
reference for the input capture and output compare functions. The TIMA counter modulo registers,
TAMODH–TAMODL, control the modulo value of the TIMA counter. Software can read the TIMA counter
value at any time without affecting the counting sequence.
The two TIMA channels are programmable independently as input capture or output compare channels.
MC68HC908EY16 • MC68HC908EY8 Data Sheet, Rev. 10
Freescale Semiconductor
193