Datasheet

Configuration Registers (CONFIG)
Data Sheet MC68HC908LJ24/LK24 — Rev. 2.1
80 Configuration Registers (CONFIG) Freescale Semiconductor
5.3 Functional Description
The configuration registers are used in the initialization of various
options. Since the various options affect the operation of the MCU, it is
recommended that these registers be written immediately after reset.
The configuration registers are located at $001D and $001F. The
configuration registers may be read at anytime.
NOTE: The CONFIG registers are one-time writable by the user after each
reset. These 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 5-2 and Figure 5-3.
Although the LVISEL[1:0] bits default to predetermined setting of
LVISEL[1:0] = 0:1 by a POR only, these bits can still be written once after
each reset other than POR.
Addr.Register Name Bit 7654321Bit 0
$001D
Configuration Register 2
(CONFIG2)
†
Read:
PEE
STOP_
IRCDIS
STOP_
XCLKEN
DIV2CLK PCEH PCEL LVISEL1 LVISEL0
Write:
Reset:0000000
††
1
††
$001F
Configuration Register 1
(CONFIG1)
†
Read:
COPRS LVISTOP LVIRSTD LVIPWRD
0
SSREC STOP COPD
Write:
Reset:0000
††
0000
† One-time writable register after each reset.
†† Reset by POR only.
= Unimplemented
Figure 5-1. CONFIG Registers Summary