Registers
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2
KEY
Key. This field is used during the two step arming process
of the Control register. This field is sensitive to the
following data patterns:
PATTERN_1 = $55
PATTERN_2 = $AA
The Control register will be in the armed state if
PATTERN_1 is written to the KEY field. The Control
register will be changed if in the armed state and
PATTERN_2 is written to the KEY field. An incorrect
sequence of patterns will cause the Control register to be
in the unarmed state.
A value of all zeros will always be returned within the
KEY field during read cycles.
ENAB
ENAB. This field determines whether or not the WDT is
enabled. If a one is written to this bit, the timer will be
enabled. A zero written to this bit will disable the timer.
The ENAB bit may only be modified on the second step
of a successful two step arming process.
ARM
ARMED. This read-only bit indicates the armed state of
the register. If this bit is a zero, the register is unarmed. If
this bit is a one, the register is armed for a write.
RES
RESOLUTION. This field determines the resolution of
the timer. The RES field may only be modified on the
second step of a successful two step arming process. The
following table shows the different options associated
with this bit.
RES
Timer Resolution
Approximate Max
Time
0000
1 us
64 msec
0001
2 us
128 msec
0010
4 us
256 msec
0011
8 us
512 msec
Summary of Contents for MVME5100 Series
Page 1: ...MVME5100 Single Board Computer Programmer s Reference Guide V5100A PG2 September 2001 Edition ...
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Page 62: ...1 34 Computer Group Literature Center Web Site Product Data and Memory Maps 1 ...
Page 278: ...3 88 Computer Group Literature Center Web Site System Memory Controller SMC 3 ...
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