U3750BM Datasheet, PDF (13/20 Pages) TEMIC Semiconductors – One Chip Telephone Circuit

TELEFUNKEN Semiconductors
Table 2 The scanning principle
Keyboard clock
Ti except T0, T1, T7
T1
T0 or T7
Scanning cycle
2 ms
2 ms
1.956 ms
22 ms
12 ms
2.2 ms
2.2 ms
2.156 ms
22 ms
13.2 ms
T0: reset of the logic keyboard
T7: acquisition of the code present at the keyboard
Scanning
U3750BM
Push button
Rev. A1: 16.07.1996
Figure 9 The scanning principle
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