Programming Model
http://www.mcg.mot.com/literature
4-45
4
enabling/disabling the pre-scaler’s counter. Note that
clearing EN does not clear any of the programmable
clock’s registers.
PLS
When PLS is set, the programmable clock output is
asserted for one BCK period. When PLS is cleared, the
programmable clock output toggles creating a square
wave.
PLTY
PLTY controls the polarity of the programmable clock
output. When PLTY is cleared, the negated (and cleared)
state of the output is a logic 0, and the asserted state is a
logic 1. When PLTY is set, the opposite is true.
Programmable Clock Timer Register
When enabled, the programmable clock timer counter increments until it
matches the value contained in this register, at which time it rolls over and
resumes counting. The effect is that the frequency of the programmable
clock output is the frequency of the (pre-scaler output)/(the-value-in-this-
register + 1). For example, if the PLS bit is cleared, PLS2-0 are %000, and
the timer register contains $0001, then the programmable clock output
frequency is BCK/4 = 8 MHz if BCK = 32 MHz. For the pulsed output, the
formula for the period of the frequency of the recurring pulse is 1/((pre-
scaler output)/ (the-value-in-this-register + 1)). For example, if the PLS
bit is set, PLS2-0 are %001, and the timer register contains $0001, then the
programmable clock frequency of the pulsed output is BCK/4 = 8 MHz if
BCK = 32 MHz.
ADR/SIZ
$FFFBC082 (16 bits)
BIT
15
...
0
NAME
Programmable Clock Timer Register
OPER
R/W
RESET
0 R
Содержание MVME172
Страница 1: ...MVME172 VME Embedded Controller Programmer s Reference Guide VME172A PG2 Edition of February 1999 ...
Страница 6: ...Place holder ...
Страница 18: ...xviii ...
Страница 78: ...1 60 Computer Group Literature Center Web Site Board Description and Memory Maps 1 ...
Страница 332: ...5 42 Computer Group Literature Center Web Site MCECC 5 ...
Страница 336: ...A 4 Related Documentation A ...
Страница 340: ...VMEchip2 Tick Timer 1 Periodic Interrupt Example B 4 Computer Group Literature Center Web Site B ...
Страница 352: ...Index IN 12 Computer Group Literature Center Web Site I N D E X ...
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