Advance Information MC68HC908MR16/MC68HC908MR32 — Rev. 4.0
226 Timer Interface B (TIMB) MOTOROLA
Timer Interface B (TIMB)
12.2 Introduction
This section describes the timer interface module B (TIMB). The TIMB is
a 2-channel timer that provides:
Timing reference with input capture
Output compare
Pulse-width modulation functions
Figure 12-1 is a block diagram of the TIMB.
NOTE: The TIMB module is not available in the 56-pin shrink dual in-line
package (SDIP).
12.3 Features
Features of the TIMB include:
Two input capture/output compare channels:
Rising-edge, falling-edge, or any-edg e input capture trigger
Set, clear, or toggle output compare action
Buffered and unbuffered pulse-width modulation (PWM) signal
generation
Programmable TIMB clock input:
7-frequency internal bus clock prescaler selection
External TIMB clock input (4-MHz maximum frequency)
Free-running or modulo up-count op eration
Toggle any channel pin on overflo w
TIMB counter stop and reset bits
12.4 Functional Description
Figure 12-1 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 com pare functions. Th e 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.