參數(shù)資料
型號: 74F525
廠商: National Semiconductor Corporation
元件分類: 通用總線功能
英文描述: Programmable Counter
中文描述: 可編程計數(shù)器
文件頁數(shù): 5/10頁
文件大?。?/td> 184K
代理商: 74F525
Timing Diagrams
(Continued)
TL/F/9547–8
FIGURE 4. MODE 6
M
n
e
110
j
With XTR HIGH, the rising edge of CP loads data from the latches to the counter.
k
With XTR LOW, the rising edge of CP begins the count, and Q goes HIGH.
l
When the count reaches zero, Q goes LOW, and Q/2 toggles state. Bringing XTR HIGH before count reaches zero will reload the counter, but not affect Q.
Notes:
Loading N
e
0 halts counter; loading N
e
1 will result in undefined operation.
Pulse width
e
(2/CP)
*
(N
b
1)
TL/F/9547–9
FIGURE 5. MODE 7
M
n
e
111
j
With XTR HIGH, the rising edge of CP, loads data from the latches to the counter.
k
On the falling edge of XTR, the rising edge of CP begins count-down.
l
When count reaches zero, Q goes HIGH for one period of CP, and Q/2 toggles on the Q rising edge.
m
On the rising edge of CP on which Q goes LOW, the counters are reloaded.
n
Count-down begins again.
5
相關PDF資料
PDF描述
74F525PCX Programmable Counter
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74F676SPC 16-Bit Serial/Parallel-In, Serial-Out Shift Register
74F676SC 16-Bit Serial/Parallel-In, Serial-Out Shift Register
74F676PC 16-Bit Serial/Parallel-In, Serial-Out Shift Register
相關代理商/技術參數(shù)
參數(shù)描述
74F525 WAF 制造商:Fairchild Semiconductor Corporation 功能描述:
74F525DC 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog Timer Circuit
74F525PC 制造商:Texas Instruments 功能描述: 制造商:National Semiconductor Corporation 功能描述:F/FAST SERIES, ASYN POSITIVE EDGE TRIGGERED DOWN DIVIDE BY N COUNTER, PDIP28
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74F525QC 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog Timer Circuit