Chapter 5 Resets, Interrupts, and General System Control
MC9S08DV60 Series Data Sheet, Rev 2
78
Freescale Semiconductor
5.8.4
System Options Register 1 (SOPT1)
This high page register is a write-once register so only the rst write after reset is honored. It can be read
at any time. Any subsequent attempt to write to SOPT1 (intentionally or unintentionally) is ignored to
avoid accidental changes to these sensitive settings. This register should be written during the user’s reset
initialization program to set the desired controls even if the desired settings are the same as the reset
settings.
76543210
R
COPT
STOPE
SCI2PS
IICPS
000
W
Reset:
11000000
= Unimplemented or Reserved
Figure 5-5. System Options Register 1 (SOPT1)
Table 5-5. SOPT1 Register Field Descriptions
Field
Description
7:6
COPT[1:0]
COP Watchdog Timeout — These write-once bits select the timeout period of the COP. COPT along with
COPCLKS in SOPT2 denes the COP timeout period. See
Table 5-6.5
STOPE
Stop Mode Enable — This write-once bit is used to enable stop mode. If stop mode is disabled and a user
program attempts to execute a STOP instruction, an illegal opcode reset is forced.
0 Stop mode disabled.
1 Stop mode enabled.
4
SCI2PS
SCI2 Pin Select— This write-once bit selects the location of the RxD2 and TxD2 pins of the SCI2 module.
0 TxD2 on PTF0, RxD2 on PTF1.
1 TxD2 on PTE6, RxD2 on PTE7.
3
IICPS
IIC Pin Select— This write-once bit selects the location of the SCL and SDA pins of the IIC module.
0 SCL on PTF2, SDA on PTF3.
1 SCL on PTE4, SDA on PTE5.
Table 5-6. COP Conguration Options
Control Bits
Clock Source
COP Window1 Opens
(COPW = 1)
1 Windowed COP operation requires the user to clear the COP timer in the last 25% of the selected timeout period. This column
displays the minimum number of clock counts required before the COP timer can be reset when in windowed COP mode
(COPW = 1).
COP Overow Count
COPCLKS
COPT[1:0]
N/A
0:0
N/A
COP is disabled
0
0:1
1 kHz
N/A
25 cycles (32 ms2)
2 Values shown in milliseconds based on t
tolerance of this value.
0
1:0
1 kHz
N/A
28 cycles (256 ms1)
0
1:1
1 kHz
N/A
210 cycles (1.024 s1)
1
0:1
Bus
6144 cycles
213 cycles
1
1:0
Bus
49,152 cycles
216 cycles
1
1:1
Bus
196,608 cycles
218 cycles