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AS1115
Datasheet - Detailed Description
Display-Test Mode
The AS1115 can detect open or shorted LEDs. Readout of either open LEDs or short LEDs is possible, as well as a OR
relation of open and short.
Note:
All settings of the digit- and control-registers are maintained.
Table 14.
Testmode Register
Summary
D7
D6
D5
D4
X
RSET_short
RSET_open
LED_global
LED_test
LED Diagnostic Registers
These eight registers contain the result of the LED open/short test for the individual LED of each digit.
Note:
If one or more short occures in the LED array, detection of individual LED fault could become ambiguous.
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
Selecting RSET Resistor Value and Using External Drivers on page 19
). 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.
D3
D2
D1
D0
LED_open
LED_short
DISP_test
Table 15. 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
SET
is open
0: R
SET
correct; 1: R
SET
is open
Checks if external resistor R
SET
is shorted
0: R
SET
correct; 1: R
SET
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
RSET_open
0
R
D6
RSET_short
0
R
D7
0
-
Table 16. LED Diagnostic Register Address
Register
HEX
Address
0x14
DIG0
0x15
DIG1
0x16
DIG2
0x17
DIG3
Segment
D4
Register
HEX
Address
0x18
0x19
0x1A
0x1B
Segment
D4
Digit
D7
D6
D5
D3
D2
D1
D0
Digit
DIG4
DIG5
DIG6
DIG7
D7
D6
D5
D3
D2
D1
D0
DP
A
B
C
D
E
F
G
DP
A
B
C
D
E
F
G