Table 3. keys fifo register format (0x00) – Rainbow Electronics MAX7359 User Manual
Page 8
MAX7359
2-Wire Interfaced Low-EMI
Key Switch Controller/GPO
8
_______________________________________________________________________________________
KEYS FIFO REGISTER DATA
SPECIAL FUNCTION
D7
D6
D5
D4
D3
D2
D1
D0
The key number indicated by D5:D0 is a key event. D7
is always for a key press of key 62 and key 63. When
D7 is 0, the key read is the last data in the FIFO. When
D7 is 1, there is more data in the FIFO. When D6 is 1,
key data read from FIFO is a key release. When D6 is
0, key data read from FIFO is a key press.
FIFO
empty
flag
Key
release
flag
X
X
X
X
X
X
FIFO is empty.
0
0
1
1
1
1
1
1
FIFO is overflow. Continue to read data in FIFO.
0
1
1
1
1
1
1
1
Key 63 is pressed. Read one more time to determine
whether there is more data in FIFO.
1
0
1
1
1
1
1
1
Key 63 is released. Read one more time to determine
whether there is more data in FIFO.
1
1
1
1
1
1
1
1
Key repeat. Indicates the last data in FIFO.
0
0
1
1
1
1
1
0
Key repeat. Indicates more data in FIFO.
0
1
1
1
1
1
1
0
Key 62 is pressed. Read one more time to determine
whether there is more data in FIFO.
1
0
1
1
1
1
1
0
Key 62 is released. Read one more time to determine
whether there is more data in FIFO.
1
1
1
1
1
1
1
0
Table 3. Keys FIFO Register Format (0x00)