MC68HC908GZ8 Datasheet, PDF (103/344 Pages) Motorola, Inc – Microcontrollers

Data Sheet — MC68HC908GZ8
Section 8. Configuration Register (CONFIG)
8.1 Introduction
This section describes the configuration registers, CONFIG1 and CONFIG2. The
configuration registers enable or disable these options:
• Stop mode recovery time (32 CGMXCLK cycles or 4096 CGMXCLK cycles)
• COP timeout period (2¹⁸ – 2⁴ or 2¹³ – 2⁴ COPCLK cycles)
• STOP instruction
• Computer operating properly module (COP)
• Low-voltage inhibit (LVI) module control and voltage trip point selection
• Enable/disable the oscillator (OSC) during stop mode
• Enable/disable an extra divide by 128 prescaler in timebase module
• Enable for scalable controller area network (MSCAN)
8.2 Functional Description
The configuration registers are used in the initialization of various options. The
configuration registers can be written once after each reset. All of the configuration
register bits are cleared during reset. Since the various options affect the operation
of the microcontroller unit (MCU), it is recommended that these registers be written
immediately after reset. The configuration registers are located at $001E and
$001F and may be read at anytime.
NOTE:
On a FLASH device, the options except LVI5OR3 are one-time writable by the user
after each reset. The LVI5OR3 bit is one-time writable by the user only after each
POR (power-on reset). The CONFIG registers are not in the FLASH memory but
are special registers containing one-time writable latches after each reset. Upon a
reset, the CONFIG registers default to predetermined settings as shown in Figure
8-1 and Figure 8-2.
MC68HC908GZ8
Freescale Semiconductor
Configuration Register (CONFIG)
Data Sheet
103