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AS1115
Datasheet - Detailed Description
Initial Power-Up
On initial power-up, the AS1115 registers are reset to their default values, the display is blanked, and the device goes
into shutdown mode. At this time, all registers should be programmed for normal operation.
Note:
The default settings enable only scanning of one digit; the internal decoder is disabled and the Intensity Control
Register (
see page 17
) is set to the minimum values.
Shutdown Mode
The AS1115 devices feature a shutdown mode, where they consume only 200nA (typ) current. Shutdown mode is
entered via a write to the Shutdown Register (see
Table 7
). During shutdown mode the Digit-Registers maintain their
data.
Shutdown mode can either be used as a means to reduce power consumption or for generating a flashing display
(repeatedly entering and leaving shutdown mode). For minimum supply current in shutdown mode, logic input should
be at GND or V
DD
(CMOS logic level).
When entering or leaving shutdown mode, the Feature Register is reset to its default values (all 0s) when Shutdown
Register bit D7 (page 13) = 0.
Note:
When
Shutdown Register bit D7 = 1, the Feature Register is left unchanged when entering or leaving shut-
down mode. If the AS1115 is used with an external clock, Shutdown Register bit D7 should be set to 1 when
writing to the Shutdown Register.
Digit- and Control-Registers
The AS1115 devices contain 8 Digit-Registers,11 control-registers and 10 diagnostic-registers, which are listed in
Table
6
. All registers are selected using a 8-bit address word, and communication is done via the I2C interface.
!
Digit Registers – These registers are realized with an on-chip 64-bit memory. Each digit can be controlled directly
without rewriting the whole register contents.
!
Control Registers – These registers consist of decode mode, display intensity, number of scanned digits, shut-
down, display test and features selection registers.
Table 6. Register Address Map
T
Register
Address
D9
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Page
D15:D13
000
000
000
000
000
000
000
000
000
000
000
000
001
000
000
000
000
000
000
D12
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
D11
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
D10
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
D8
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
D7:D0
D
Digit 0
Digit 1
Digit 2
Digit 3
Digit 4
Digit 5
Digit 6
Digit 7
(see
Table 9 on page 14
,
Table 10 on page 14
and
Table 11 on page 15
)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
13
17
17
12
N/A
18
13
C
Decode-Mode
Global Intensity
Scan Limit
Shutdown
Self-Adressing
Feature
Display Test Mode
DIG0:DIG1 Intensity
DIG2:DIG3 Intensity
DIG4:DIG5 Intensity
DIG6:DIG7 Intensity
(
see Table 8 on page 13
)
(
see Table 17 on page 17
)
(
see Table 19 on page 17
)
(
see Table 7 on page 13
)
(
see Table 20 on page 18
)
(
see Table 14 on page 16
)
(
see Table 18 on page 17
)
(
see Table 18 on page 17
)
(
see Table 18 on page 17
)
(
see Table 18 on page 17
)