MC68HC908LB8_05 Datasheet, PDF (59/234 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Chapter 5
Configuration Register (CONFIG)
5.1 Introduction
This section describes the configuration registers, CONFIG1 and CONFIG2. The configuration registers
enable or disable these options:
• COP timeout period (2¹⁸ – 2⁴ or 2¹³ – 2⁴ BUSCLKX4 cycles)
• STOP instruction
• Stop mode recovery (32 x BUSCLKX4 cycles or
4096 x BUSCLKX4 cycles)
• Computer operating properly module (COP)
• Low-voltage inhibit (LVI) module control
• IRQ pin
• RST pin
• OSC option selection
5.2 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 are one-time writable by the user after
each 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 5-1 and Figure 5-2.
MC68HC908LB8 Data Sheet, Rev. 1
Freescale Semiconductor
59