74F525PCX NSC [National Semiconductor], 74F525PCX Datasheet - Page 4

• Manufacturer Part Number: 74F525PCX
• Description: Programmable Counter
• Manufacturer: NSC [National Semiconductor]

Timing Diagrams
Note Once the count reaches zero the counter can be reloaded with XTR HIGH
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With XTR HIGH the rising edge of CP loads data from the latches to the counter
With XTR LOW the rising edge of CP begins count-down cycle
When the count reaches zero Q goes HIGH and Q 2 toggles state
The next occurrence of XTR clears Q
With XTR HIGH the rising edge of CP loads data from the latches to the counter
With XTR LOW the rising edge of CP begins the count-down cycle
When the count reaches zero Q goes HIGH for one period of CP and Q 2 toggles state
With XTR HIGH the rising edge of CP loads data from the latches into the counter
With XTR LOW the rising edge of CP begins the count-down
With XTR HIGH during count-down the rising edge of CP does nothing
When the count reaches zero Q goes HIGH for one clock cycle and Q 2 toggles state
FIGURE 1 MODE 0 and MODE 1 (Inverse Output of Mode 0)
FIGURE 2 MODE 2 and MODE 3 (Inverse Output of Mode 2)
FIGURE 3 MODE 4 and MODE 5
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000 001
010 011
100 101
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TL F 9547– 5
TL F 9547– 6
TL F 9547– 7