MC68HC08AS32 Datasheet, PDF (183/280 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

Data Sheet — MC68HC08AS32
Section 13. System Integration Module (SIM)
13.1 Introduction
This section describes the system integration module (SIM), which supports up to
24 external and/or internal interrupts. The SIM is a system state controller that
coordinates CPU and exception timing. Together with the central processor unit
(CPU), the SIM controls all MCU activities. A block diagram of the SIM is shown in
Figure 13-2. Figure 13-3 is a summary of the SIM input/output (I/O) registers.
The SIM is responsible for:
• Bus clock generation and control for CPU and peripherals:
– Stop/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
MC68HC08AS32 — Rev. 4.1
Freescale Semiconductor
Data Sheet
183