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AS1116
Datasheet - Detailed Description
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 17
). 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.
Display brightness is controlled by an integrated pulse-width modulator which is controlled by the lower-nibble of the Intensity Control Register.
The modulator scales the average segment-current in 16 steps from a maximum of 15/16 down to 1/16 of the peak current set by R
SET
.
Scan-Limit Register (0x0B)
The Scan-Limit Register controls which of the digits are to be displayed. When all 8 digits are to be displayed, the update frequency is typically
0.8kHz. If the number of digits displayed is reduced, the update frequency is increased. The frequency can be calculated using 8fOSC/N, where
N is the number of digits. Since the number of displayed digits influences the brightness, R
SET
should be adjusted accordingly.
Note:
To avoid differences in brightness this register should not be used to blank parts of the display (leading zeros).
Table 16. Intensity Register Format
Duty Cycle
HEX Code
Register Data
D2
0
0
0
0
1
1
1
1
Duty Cycle
HEX Code
Register Data
D2
0
0
0
0
1
1
1
1
MSB
0
0
0
0
0
0
0
0
D1
0
0
1
1
0
0
1
1
LSB
0
1
0
1
0
1
0
1
MSB
1
1
1
1
1
1
1
1
D1
0
0
1
1
0
0
1
1
LSB
0
1
0
1
0
1
0
1
1/16 (min on)
2/16
3/16
4/16
5/16
6/16
7/16
8/16
0xX0
0xX1
0xX2
0xX3
0xX4
0xX5
0xX6
0xX7
9/16
10/16
11/16
12/16
13/16
14/16
15/16
0xX8
0xX9
0xXA
0xXB
0xXC
0xXD
0xXE
0xXF
15/16 (max on)
Table 17. Intensity Register Address
Register HEX Address
Register Data
Type
Global
Digit
Digit
Digit
Digit
D7:D4
X
D3:D0
0x0A
0x10
0x11
0x12
0x13
Global Intensity
Digit 0 Intensity
Digit 2 Intensity
Digit 4 Intensity
Digit 6 Intensity
Digit 1 Intensity
Digit 3 Intensity
Digit 5 Intensity
Digit 7 Intensity
Table 18. Scan-Limit Register Format (Address (HEX) = 0x0B))
Scan Limit
HEX
Code
0xX0
0xX1
0xX2
0xX3
Register Data
D7:D3
D2
X
X
X
X
Scan Limit
HEX
Code
0xX4
0xX5
0xX6
0xX7
Register Data
D7:D3
D2
X
X
X
X
D1
0
0
1
1
D0
0
1
0
1
D1
0
0
1
1
D0
0
1
0
1
Display digit 0 only
Display digits 0:1
Display digits 0:2
Display digits 0:3
0
0
0
0
Display digits 0:4
Display digits 0:5
Display digits 0:6
Display digits 0:7
1
1
1
1