MOTOROLA
D-14
REGISTER SUMMARY
MC68331
USER’S MANUAL
D
Y = M111, where M is the logic state of the module mapping (MM) bit in the SIMCR
D.3.1 SIMCR
— Module Configuration Register
$YFFA00
SIMCR controls system configuration. SIMCR can be read or written at any time, ex-
cept for the module mapping (MM) bit, which can only be written once.
EXOFF — External Clock Off
0 = The CLKOUT pin is driven from an internal clock source.
1 = The CLKOUT pin is placed in a high-impedance state.
FRZSW — Freeze Software Enable
0 = When FREEZE is asserted, the software watchdog and periodic interrupt timer
counters continue to run.
1 = When FREEZE is asserted, the software watchdog and periodic interrupt timer
counters are disabled, preventing interrupts during software debug.
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
$YFFA50
$YFFA52
$YFFA54
$YFFA56
$YFFA58
$YFFA5A
$YFFA5C
$YFFA5E
$YFFA60
$YFFA62
$YFFA64
$YFFA66
$YFFA68
$YFFA6A
$YFFA6C
$YFFA6E
$YFFA70
$YFFA72
$YFFA74
$YFFA76
$YFFA78
$YFFA7A
$YFFA7C
$YFFA7E
CHIP-SELECT BASE 1 (CSBAR1)
CHIP-SELECT OPTION 1 (CSOR1)
CHIP-SELECT BASE 2 (CSBAR2)
CHIP-SELECT OPTION 2 (CSOR2)
CHIP-SELECT BASE 3 (CSBAR3)
CHIP-SELECT OPTION 3 (CSOR3)
CHIP-SELECT BASE 4 (CSBAR4)
CHIP-SELECT OPTION 4 (CSOR4)
CHIP-SELECT BASE 5 (CSBAR5)
CHIP-SELECT OPTION 5 (CSOR5)
CHIP-SELECT BASE 6 (CSBAR6)
CHIP-SELECT OPTION 6 (CSOR6)
CHIP-SELECT BASE 7 (CSBAR7)
CHIP-SELECT OPTION 7 (CSOR7)
CHIP-SELECT BASE 8 (CSBAR8)
CHIP-SELECT OPTION 8 (CSOR8)
CHIP-SELECT BASE 9 (CSBAR9)
CHIP-SELECT OPTION 9 (CSOR9)
CHIP-SELECT BASE 10 (CSBAR10)
CHIP-SELECT OPTION 10 (CSOR10)
NOT USED
NOT USED
NOT USED
NOT USED
NOT USED
NOT USED
NOT USED
NOT USED
15
14
13
12
0
11
10
0
9
8
7
6
5
0
4
0
3
0
EXOFF
FRZSW
FRZBM
SLVEN
SHEN
SUPV
MM
IARB
RESET:
0
0
0
0
DATA11
0
0
0
1
1
0
0
1
1
1
1
Table D-3 SIM Address Map
Access
Address
15
8 7
0