MC68HC908GT16 Datasheet, PDF (296/412 Pages) Motorola, Inc – Microcontrollers

System Integration Module (SIM)
19.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
19.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .313
19.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .315
19.8 SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .316
19.8.1 SIM Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 316
19.8.2 SIM Reset Status Register . . . . . . . . . . . . . . . . . . . . . . . . 318
19.8.3 SIM Break Flag Control Register . . . . . . . . . . . . . . . . . . . . 319
19.2 Introduction
This section describes the system integration module (SIM). Together
with the central processor unit (CPU), the SIM controls all microconroller
unit (MCU) activities. A block diagram of the SIM is shown in
Figure 19-1. Table 19-1 is a summary of the SIM input/output (I/O)
registers. 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:
– 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
Table 19-1 shows the internal signal names used in this section.
Technical Data
296
MC68HC908GT16 • MC68HC908GT8 — Rev. 2
System Integration Module (SIM)
MOTOROLA