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AS1122

Datasheet - D e t a i l e d D e s c r i p t i o n

Register Access

Before data are accepted by the AS1122, an identifier needs to be send in advance. Only 3 defined identifiers will be recognized, all other bit

combinations will be ignored.

The identifier maps the input register to the identified register and all data on pin SDI will be clocked into this register. This selection is valid as

long as no internal LD signal is triggered. When data is latched into the device the identifier selection is reset and for the next data word a new

identifier needs to be send. Every identifier requires a certain data section length. If this length is not corresponding with the identifier, the data

will be ignored.

Note:

Bit3 of the identifier is an global on/off bit. When bit3 of any identifier is set to logic ‘0’ and the OEN bit of the command register (see

Figure 7 on page 14) is ‘0’ (per default), the output channels are immediately turned on.

Dot Correction (DC)

The AS1122 offers a 6 bit (64 steps) Dot Correction per Output channel. After sending the 8 bit identifier for access to the DC register the device

is waiting for 72 bits to receive. If more or less bits are send the whole dataword will be ignored.

Figure 25. Dot Correction Input Timing Diagram

For n devices in a chain only one identifier needs to be send to set all n devices to the same register setting.

Figure 26. Dot Correction for n-devices

Table 6. Identifier

Identifier

Bit

Data Section

length

Description

7

6

5

4

3

2

1

0

Dot Correction Data

1

1

0

0

1 / 0

0

0

1

72 bits

writes Data into Dot Correction Register

PWM Data

1

1

0

0

1 / 0

0

1

0

144 bits

writes Data into PWM Register

Command Data

1

1

0

0

1 / 0

1

0

0

8 bits

writes Data into Command Register