MAX7347 MAXIM [Maxim Integrated Products], MAX7347 Datasheet - Page 17

• Manufacturer Part Number: MAX7347
• Description: 2-Wire Interfaced Low-EMI Key Switch and Sounder Controllers
• Manufacturer: MAXIM [Maxim Integrated Products]

Table 11. Interrupt Register Format
* Read-only register bits; write data is ignored. Reading the interrupt register does clear an alert event INT, but does not clear a key-
scan event INT. INT caused by key-scan event(s) is cleared when FIFO is emptied.
Current INT is due to key-scan event(s)
Current INT is due to alert event
Current INT is due to both key-scan event(s)
and alert event
INT has not been asserted
INT has been asserted
INT output pin is NOT asserted; INT output
pin is used as a general-purpose output
called INT port under control of bit D6 in
ports register; INT status bits D5, D6, D7 are
still set and cleared in the normal way at the
end of every debounce cycle as if bits D4–D0
were set to 00001
Key-scan INT is asserted at the end of every
debounce cycle, if new key(s) is debounced
Key-scan INT is asserted at the end of every
2 debounce cycles, if new key(s) is
debounced
Key-scan INT is asserted at the end of every
29 debounce cycles, if new key(s) is
debounced
Key-scan INT is asserted at the end of every
30 debounce cycles, if new key(s) is
debounced
Key-scan INT is asserted at the end of every
31 debounce cycles, if new key(s) is
debounced
Power-up default setting
INTERRUPT REGISTER
REGISTER
______________________________________________________________________________________
-—
2-Wire Interfaced Low-EMI Key Switch
CODE (hex)
ADDRESS
0x03
0x03
0x03
0x03
0x03
0x03
0x03
0x03
0x03
0x03
0x03
0x03
0x03
STATUS*
and Sounder Controllers
INT
D7
—
X
X
X
X
X
X
1
1
1
0
1
0
EVENT*
ALERT
ALERT
EVENT
D6
—
X
X
X
X
X
X
0
1
1
0
0
REGISTER DATA
EVENT*
EVENT
SCAN
SCAN
KEY-
KEY-
D5
—
X
X
X
X
X
X
1
0
1
0
0
D4
—
X
X
X
X
X
0
0
0
1
1
1
0
KEY-SCAN INTERRUPT
D3
FREQUENCY
—
X
X
X
X
X
0
0
0
1
1
1
0
D2
—
X
X
X
X
X
0
0
0
1
1
1
0
D1
—
X
X
X
X
X
0
0
1
0
1
1
0
D0
—
X
X
X
X
X
0
1
0
1
0
1
0
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