Datasheet

MC68HC908GZ16 • MC68HC908GZ8 Data Sheet, Rev. 4
Freescale Semiconductor 213
Chapter 16
System Integration Module (SIM)
16.1 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 16-1. Table 16-1 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 16-1. 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