MC68HC908GR8A_07 Datasheet, PDF (157/260 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 14
System Integration Module (SIM)
14.1 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 14-1. Table 14-1 is a summary of the SIM input/output (I/O) registers. The SIM is a system state
controller that coordinates CPU and exception timing.
STOP/WAIT
CONTROL
SIM
COUNTER
MODULE STOP
MODULE WAIT
CPU STOP (FROM CPU)
CPU WAIT (FROM CPU)
SIMOSCEN (TO CGM)
CGMXCLK (FROM CGM)
CGMOUT (FROM CGM)
÷2
RESET
PIN LOGIC
V_DD
INTERNAL
PULLUP
DEVICE
CLOCK
CONTROL
CLOCK GENERATORS
POR CONTROL
RESET PIN CONTROL
SIM RESET STATUS REGISTER
MASTER
RESET
CONTROL
RESET
INTERNAL CLOCKS
FORCED MONITOR MODE ENTRY
LVI (FROM LVI MODULE)
ILLEGAL OPCODE (FROM CPU)
ILLEGAL ADDRESS (FROM ADDRESS
MAP DECODERS)
COP (FROM COP MODULE)
INTERRUPT CONTROL
AND PRIORITY DECODE
INTERRUPT SOURCES
CPU INTERFACE
Figure 14-1. SIM Block Diagram
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
Freescale Semiconductor
157