AS1115 austriamicrosystems AG, AS1115 Datasheet - Page 15

• Manufacturer Part Number: AS1115
• Description: Interfaced LED Driver
• Manufacturer: austriamicrosystems AG

Table 13. LED Diagnostic Register Address
AS1115
Datasheet - D e t a i l e d D e s c r i p t i o n
Table 11. No-Decode Mode Data Bits and Corresponding Segment Lines
I²C Self Addressing
If this feature is used, 2 of the 16 key readback nodes can be left open or shorted for self-addressing. This is done with
KEYA together with SEGG and SEGF. This two nodes cannot be used for key-readback in this case. After startup all
devices have the predefined adress 0000000. A single command for selfaddressing will update all connected AS1115.
This command has to be done after startup or everytime the AS1115 gets disconnected from the supply. The I²C
address definition must be done with fixed connection, since I²C detection is excluded from debounce time of key reg-
isters.
Note: A short writes a logical “1” whereas an open writes a logical “0” as address bit.
Table 12. Self Addressing Register (Address (HEX) = 0x2D))
Keyscan Register
These two registers contain the result of the keyscan input of the 16 keys. To ensure proper results the data in these
registers are updated only if the logic data scanned is stable for 20ms (debounce time). A change of the data stored
within these two registers is indicated by a logic low on the IRQ pin. The IRQ is high-impedance if a read operation on
the key scan registers is started.
Note: If I²C self addressing is used segment G&F of KEYA is used for the two LSB of the I²C address. In this case
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Register HEX Address
Corresponding Segment Line
Factory-set IC address
User-set IC address
these two nodes cannot be used as a key. Additionally the debounce time is disabled for these two bits.
The data within the keyscan register is updated continuously during every cycle (1/10 of refresh rate). There-
fore, to get a valid readback of keys it is recommended to read out the keyscan registers immediately after the
IRQ is triggered.
0x1C
0x1D
KEYB
KEYA
Key
DP
D7
D7
X
X
DP
D7
D6
D6
A
X
X
Revision 1.03
D6
A
D5
D5
B
X
X
D5
B
D4
D4
C
X
X
D4
C
Segment
D3
D3
D
X
X
D3
D
D2
D2
E
X
X
D2
E
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D1
D1
F
X
X
D1
F
15 - 24
D0
D0
D0
G
0
1
G