MC9S08SH32 Datasheet, PDF (69/328 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 5 Resets, Interrupts, and General System Control
5.7.4 System Options Register 1 (SOPT1)
This high page register is a write-once register so only the first 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. SOPT1 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.
7
R
W
Reset:
1
POR:
1
LVR:
1
1 _{u = unaffected}
6
5
4
COPT
0
STOPE
3
2
0
IICPS
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 5-5. System Options Register 1 (SOPT1)
Table 5-6. SOPT1 Register Field Descriptions
1
BKGDPE
1
1
1
0
RSTPE
u⁽¹⁾
0
u
Field
Description
7:6
COP Watchdog Timeout — These write-once bits select the timeout period of the COP. COPT along with
COPT[1:0] COPCLKS in SOPT2 defines the COP timeout period. See Table 5-1.
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.
2
IICPS
IIC Pin Select — This bit selects the location of the SDA and SCL pins of the IIC module.
0 SDA on PTA2, SCL on PTA3.
1 SDA on PTB6, SCL on PTB7.
1
BKGDPE
Background Debug Mode Pin Enable — This write-once bit when set enables the PTA4/ACMPO/BKGD/MS
pin to function as BKGD/MS. When clear, the pin functions as one of its output-only alternative functions. This
pin defaults to the BKGD/MS function following any MCU reset.
0 PTA4/ACMPO/BKGD/MS pin functions as PTA4 or ACMPO.
1 PTA4/ACMPO/BKGD/MS pin functions as BKGD/MS.
0
RSTPE
RESET Pin Enable — This write-once bit when set enables the PTA5/IRQ/TCLK/RESET pin to function as
RESET. When clear, the pin functions as one of its alternative functions. This pin defaults to a general-purpose
input port function following a POR reset. When configured as RESET, the pin will be unaffected by LVR or other
internal resets. When RSTPE is set, an internal pullup device is enabled on RESET.
0 PTA5/IRQ/TCLK/RESET pin functions as PTA5, IRQ or TCLK.
1 PTA5/IRQ/TCLK/RESET pin functions as RESET.
MC9S08SH32 Series Data Sheet, Rev. 2
Freescale Semiconductor
69
PRELIMINARY