AS1112
Datasheet - D e t a i l e d D e s c r i p t i o n
9 Detailed Description
Serial Interface
The AS1112 features a serial interface (CLK, SDI, SDO, LD, OEN and MODE), which can be connected to microcontrollers or digital signal pro-
cessors in various configurations.
The rising edge of the CLK signal shifts data from pin SDI to the internal register. After all data is clocked in, the serial data is latched into the
internal registers at the rising edge of the LD signal.
Note:
All data is clocked in with the MSB first.
Figure 9. Serial Data Input Timing Diagram
Dot Correction Mode
Data Input Cycle
Greyscale Mode
Data Input Cycle
MODE
SDI
CLK
SDO
Error Information Output
The open-drain output pin XERR indicates if the device is in one of the two error conditions: overtemperature flag or open LED detect. During
normal operation, the internal transistor connected to pin XERR is turned off and the voltage on XERR is pulled up to V
CC
through an external
pullup resistor.
If an overtemperature or open LED condition is detected, the internal transistor is switched on, and XERR is pulled to GND. Because XERR is an
open-drain output, multiple AS1112 devices can be ORed together and pulled up to V
CC
with a single pullup resistor
This reduces the number of signals needed to report a system error.
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To differentiate the overtemperature flag from the open LED detect flag from pin XERR, the open LED detect flag can be masked out by setting
OEN = 1
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ts
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t
H3
t
SU3
t
H3
LD
DCn-1
LSB
DCn
MSB
DCn
LSB
t
H2
GSn
MSB
GSn
LSB
DCn+1
MSB
t
SU2
t
SU2
1
96
1
192
1
DCn-1
MSB
DCn-1
MSB-1
DCn-1
LSB
DCn
MSB
X
X
SID
MSB
X
Revision 1.13
lv
Dot Correction Mode
Data Input Cycle
DCn-1
MSB-1
2
al
8 - 19
Multiple AS1112 devices can be cascaded by connecting the SDO pin of one device with pin SDI of the next device
The SDO pin can also be connected to the microcontroller to receive status information from the AS1112. The serial data format is 96-bit or 192-
bit wide, depending on mode of the device
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AMSCO [ AUSTRIAMICROSYSTEMS AG ]
