SYSTEM INTEGRATION MODULE
M68HC16 Z SERIES
5-2
USER’S MANUAL
Figure 5-1 System Integration Module Block Diagram
5.2 System Configuration
The SIM configuration register (SIMCR) governs several aspects of system operation.
The following paragraphs describe those configuration options controlled by SIMCR.
5.2.1 Module Mapping
Control registers for all the modules in the microcontroller are mapped into a 4-Kbyte
block. The state of the module mapping (MM) bit in the SIM configuration register
(SIMCR) determines where the control register block is located in the system memory
map. When MM = 0, register addresses range from $7FF000 to $7FFFFF; when MM
= 1, register addresses range from $FFF000 to $FFFFFF.
In M68HC16 Z-series MCUs, ADDR[23:20] follow the logic state of ADDR19 unless
externally driven. MM corresponds to IMB ADDR23. If MM is cleared, the SIM maps
IMB modules into address space $7FF000 – $7FFFFF, which is inaccessible to the
CPU16. Modules remain inaccessible until reset occurs. The reset state of MM is one,
but the bit can be written once. Initialization software should make certain MM remains
set.
Z SERIES SIM BLOCK
SYSTEM CONFIGURATION
CLOCK SYNTHESIZER
CHIP-SELECTS
EXTERNAL BUS INTERFACE
FACTORY TEST
CLKOUT
EXTAL
MODCLK
CHIP-SELECTS
EXTERNAL BUS
RESET
TSC
FREEZE/QUOT
XTAL
SYSTEM PROTECTION
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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