MC68HC705V12CFN MOTOROLA [Motorola, Inc], MC68HC705V12CFN Datasheet - Page 87

• Manufacturer Part Number: MC68HC705V12CFN
• Description: The Motorola microcontroller
• Manufacturer: MOTOROLA [Motorola, Inc]

8.1 Contents
8.2 Introduction
MC68HC705V12
MOTOROLA
Advance Information — MC68HC705V12
—
Rev. 3.0
8.2
8.3
8.4
8.5
8.6
The core timer for this device is a 12-stage multi-functional ripple
counter. Features include:
As seen in in
then drives an 8-bit ripple counter. The value of this 8-bit ripple counter
can be read by the CPU at any time by accessing the core timer counter
register (CTCR) at address $09. A timer overflow function is
implemented on the last stage of this counter, giving a possible interrupt
rate of the internal peripheral clock(E)/1024. This point is then followed
by two more stages, with the resulting clock (E/2048) driving the RTI
circuit. The RTI circuit consists of three divider stages with a 1-of-4
selector. The output of the RTI circuit is further divided by eight to drive
the mask optional COP watchdog timer circuit. The RTI rate selector bits
•
•
•
•
Timer overflow
Power-on reset (POR)
Real-time interrupt (RTI)
Computer operating properly (COP) watchdog timer
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87
Core Timer Status and Control Register. . . . . . . . . . . . . . . . . .89
Computer Operating Properly (COP) Reset . . . . . . . . . . . . . . .91
Core Timer Counter Register . . . . . . . . . . . . . . . . . . . . . . . . . .92
Core Timer during Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . .92
Figure
Core Timer
8-1, the internal peripheral clock is divided by four
Section 8. Core Timer
Advance Information
87