9 - 21
AS1106, AS1107
Datasheet - Detailed Description
8.4 Shutdown Mode
The AS1106/AS1107 devices feature a shutdown mode, where they consume only 10μA (max) current. Shutdown mode is entered via a write to
the Shutdown Register (see
Table 8
). For the AS1106, at that point, all segment current sources are pulled to ground and all digit drivers are
connected to V
DD
, so that all segments are blanked. The AS1107 behavior is identical except the drivers are high impedance.
Note:
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 mnimumsupply current in shutdown mode, logic input should be at GND or V
DD
(CMOS logic level).
The devices need typically 250μs to exit shutdown mode, and during shutdown mode the AS1106/AS1107 is fully programmable. Only the
display test mode (see page 11) overrides shutdown mode.
When entering or leaving shutdown mode, the Feature Register is reset to its default values (all 0s) when Shutdown Register bit D7(page 10) =
0.
1
Note:
If the AS1106/AS1107 is used with an external clock, Shutdown Register bit D7 should be set to 1 when writing to the Shutdown Regis-
ter.
8.5 Digit- and Control-Registers
The AS1106/AS1107 devices contain 8 Digit-Registers and 6 control-registers, which are listed in
Table 7
. All registers are selected using a 4-bit
address word, and communication is done via the serial 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, shutdown, display test and fea-
tures selection registers.
1. When Shutdown Register
bit D7 = 1, the
Feature Register
is left unchanged when entering or leaving shutdown mode.
Table 7. Register Address Map
Register
HEX Code
Address
Page
D15:D12
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
D11
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
D10
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
D9
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
D8
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
No-Op
Digit 0
Digit 1
Digit 2
Digit 3
Digit 4
Digit 5
Digit 6
Digit 7
0xX0
0xX1
0xX2
0xX3
0xX4
0xX5
0xX6
0xX7
0xX8
0xX9
0xXA
0xXB
0xXC
0xXD
0xXE
0xXF
13
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
10
12
12
10
N/A
13
11
Decode-Mode
Intensity Control
Scan Limt
Shutdown
N/A
Feature
Display Test