MC68HC705MC4 Datasheet, PDF (90/99 Pages) Motorola, Inc – Microcontrollers

MC68HC705MC4 Specification Rev. 1.5
SECTION 11
CORE TIMER
The Core Timer (Ctimer) for this device is a 15-stage multi-functional ripple counter. The
features include Timer Overflow, Power-On Reset (POR), Real Time Interrupt, and COP
Watchdog Timer
Internal Bus
88
CTCR
$09 Core Timer Counter Register (CTCR)
f_op/2¹⁰
7-bit counter
f_OP/2²
Internal
Processor
f_{OP Clock}
÷4
COP
Clear
Overflow
Detect
Circuit
RTI Select Circuit
POR
TCBP
CTCSR
$08 CTCSR
CTimer Control & Status Register
CTOF RTIF CTOIE RTIE — — RT1 RT0
Interrupt Circuit
COP Watchdog
Timer (÷8)
To Interrupt
Logic
To Reset
Logic
Figure 11-1: Core Timer Block Diagram
Section 11: Core Timer
MOTOROLA
Page 81