Datasheet

MC68HC908GR16A Data Sheet, Rev. 1.0
Freescale Semiconductor 173
Chapter 15
System Integration Module (SIM)
15.1 Introduction
This section describes the system integration module (SIM). Together with the central processor unit
(CPU), the SIM controls all microcontroller unit (MCU) activities. A block diagram of the SIM is shown in
Figure 15-1. Table 15-1 is a summary of the SIM input/output (I/O) registers. The SIM is a system state
controller that coordinates CPU and exception timing.
Figure 15-1. SIM Block Diagram
STOP/WAIT
CLOCK
CONTROL
CLOCK GENERATORS
POR CONTROL
RESET PIN CONTROL
SIM RESET STATUS REGISTER
INTERRUPT CONTROL
AND PRIORITY DECODE
MODULE STOP
MODULE WAIT
CPU STOP (FROM CPU)
CPU WAIT (FROM CPU)
SIMOSCEN (TO CGM)
CGMOUT (FROM CGM)
INTERNAL CLOCKS
MASTER
RESET
CONTROL
RESET
PIN LOGIC
LVI (FROM LVI MODULE)
ILLEGAL OPCODE (FROM CPU)
ILLEGAL ADDRESS (FROM ADDRESS
MAP DECODERS)
COP (FROM COP MODULE)
INTERRUPT SOURCES
CPU INTERFACE
RESET
CONTROL
SIM
COUNTER
CGMXCLK (FROM CGM)
÷ 2
V
DD
INTERNAL
PULLUP
DEVICE
FORCED MONITOR MODE ENTRY