Advance Information MC68HC908MR16/MC68HC908MR32 — Rev. 4.0
90 System Integration Module (SIM) MOTOROLA
System Integration Module (SIM)
7.2 Introduction
This section describes the system integration module (SIM). Together
with the central processor unit (CPU), the SIM c ontrols all
microcontroller unit (MCU) activities.
A block diagram of the SIM is shown in Figure 7-1.
The SIM is a system state controller that coordinates CPU and exception
timing. The SIM is responsible for:
Bus clock generation and control for CPU and peripherals:
Wait/reset/break entry and recovery
Internal clock control
Master reset control, including power-on reset (POR) and
computer operating properly (COP) timeout
Interrupt control:
Acknowledge timing
Arbitration control timing
Vector address generation
CPU enable/disable timing
Modular architecture expandable to 128 interrupt sources
Table 7-1 shows the internal signal names used in this section.