MPC555
/
MPC556
SYSTEM CONFIGURATION AND PROTECTION
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
6-27
6.13.3 System Protection Registers
6.13.3.1 System Protection Control Register (SYPCR)
The system protection control register (SYPCR) controls the system monitors, the
software watchdog period, and the bus monitor timing. This register can be read at any
time, but can be written only once after system reset.
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
LSB
31
RESERVED
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
SYPCR
— System Protection Control Register
0x2F C004
MSB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
SWTC
RESET:
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
LSB
31
BMT
BME
RESERVED
SWF
SWE
SWRI
SWP
RESET:
1
1
1
1
1
1
1
1
0
0
0
0
0
1
1
1
Table 6-13 SYPCR Bit Descriptions
Bit(s)
Name
Description
0:15
SWTC
Software watchdog timer count. This field contains the count value of the software watchdog tim-
er.
16:23
BMT
Bus monitor timing. This field specifies the time-out period, in eight-system-clock resolution, of
the bus monitor.
24
BME
Bus monitor enable
0 = Disable bus monitor
1 = Enable bus monitor
25:27
—
Reserved
28
SWF
Software watchdog freeze
0 = Software watchdog continues to run while FREEZE is asserted
1 = Software watchdog stops while FREEZE is asserted
29
SWE
Software watchdog enable. Software should clear this bit after a system reset to disable the
SWT.
0 = Watchdog is disabled
1 = Watchdog is enabled
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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