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AS1116
Datasheet - Detailed Description
Display-Test Mode
The AS1116 can detect open or shorted LEDs. Readout of either open LEDs (D2=1) or short LEDs (D1=1) is possible, as well as a OR relation of
open and short (D1=D2=1). After a diagnostic run bit D4 can be read to clarify if an error occurred before reading out detailed diagnostic data.
Note:
Table 13.
Testmode Register
Summary
D7
D6
X
REXT_short
All settings of the digit- and control-registers are maintained.
LED Diagnostic Registers
These eight registers contain the result of the LED open/short test for the individual LED of each digit.
Note:
If more than 2 shorts occure in the LED array, detection of individual LED fault could become limited to blocs.
D5
D4
D3
D2
D1
D0
REXT_open
LED_global
LED_test
LED_open
LED_short
DISP_test
Table 14. Testmode Register Bit Description (Address (HEX) = 0x0F))
Addr: 0x0F
Address
Bit
Bit Name
Default
Access
D7:D0
D0
DISP_test
0
W
Optical display test. (Testmode for external visual test.)
0: Normal operation; 1: Run display test (All digits are tested independently
from scan limit & shutdown register.)
Starts a test for shorted LEDs. (Can be set together with D2)
0: Normal operation; 1: Activate testmode
Starts a test for open LEDs. (Can be set together with D1)
0: Normal operation; 1: Activate testmode
Indicates an ongoing open/short LED test
0: No ongoing LED test; 1: LED test in progress
Indicates that the last open/short LED test has detected an error
0: No error detected; 1: Error detected
Checks if external resistor R
EXT
is open
0: R
EXT
correct; 1: R
EXT
is open
Checks if external resistor R
EXT
is shorted
0: R
EXT
correct; 1: R
EXT
is shorted
Not used
D1
LED_short
0
W
D2
LED_open
0
W
D3
LED_test
0
R
D4
LED_global
0
R
D5
REXT_open
0
R
D6
REXT_short
0
R
D7
0
-
Table 15. LED Diagnostic Register Address
Register
HEX
Address
Digit
0x14
DIG0
0x15
DIG1
0x16
DIG2
0x17
DIG3
Segment
Register
HEX
Address
0x18
0x19
0x1A
0x1B
Segment
D7
D6
D5
D4
D3
D2
D1
D0
Digit
DIG4
DIG5
DIG6
DIG7
D7
D6
D5
D4
D3
D2
D1
D0
DP
A
B
C
D
E
F
G
DP
A
B
C
D
E
F
G