AS1116
Datasheet - D e t a i l e d D e s c r i p t i o n
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 dignostic run bit D4 can be read to clearify if an error
occurred before reading out detailed diagnostic data.
Note:
All settings of the digit- and control-registers are maintained.
Table 13.
Testmode Register
Summary
D7
X
D6
REXT_short
D5
REXT_open
D4
LED_global
D3
LED_test
D2
LED_open
D1
LED_short
D0
DISP_test
Table 14. Testmode Register Bit Description (Address (HEX) = 0x0F))
Addr: 0x0F
Bit
Bit Name
Default
Access
Address
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
D2
D3
D4
D5
D6
D7
LED_short
LED_open
LED_test
LED_global
REXT_open
REXT_short
0
0
0
0
0
0
0
W
W
R
R
R
R
-
LED Diagnostic Registers
These eight registers contain the result of the LED open/short test for the individual LED of each digit.
Table 15. LED Diagnostic Register Address
Register
HEX
Address
0x14
0x15
0x16
0x17
Segment
Digit
D7
D6 D5 D4 D3 D2 D1 D0
Register
HEX
Address
0x18
0x19
0x1A
0x1B
Segment
Digit
D7 D6 D5 D4 D3 D2 D1 D0
DIG0
DIG1
DP
DIG2
DIG3
A
B
C
D
E
F
G
DIG4
DIG5
DP
DIG6
DIG7
A
B
C
D
E
F
G
Note:
If more than 2 shorts occure in the LED array, detection of individual LED fault could become limited to blocs.
Intensity Control Register (0x0A)
The brightness of the display can be controlled by digital means using the Intensity Control Registers and by analog
means using R
SET
(see
The intensity can be
controlled globally for all digits, or for each digit individually. The global intensity command will write intensity data to all
four individual brightness registers, while the individual intesity command will only write to the associated individual
intensity register.
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