www.ti.com

Control Byte

DAC5574

SLAS407 – DECEMBER 2003

MSB

LSB

0

0

L1

L0

X

Sel1

Sel0

PD0

Table 1. Control Register Bit Descriptions

Bit Name

Bit Number/Description

L1

Load1 (Mode Select) Bit

Are used for selecting the update mode.

L2

Load0 (Mode Select) Bit

00

temporary register of a selected channel. This mode does not change the DAC output of the selected

channel.

01

LS-BYTE (or power down information) are stored in the temporary register and in the DAC register of

the selected channel. This mode changes the DAC output of the selected channel with the new data.

10

4-Channel synchronous update. The contents of MS-BYTE and LS-BYTE (or power down information)

are stored in the temporary register and in the DAC register of the selected channel. Simultaneously,

the other three channels get updated with previously stored data from the temporary register. This

mode updates all four channels together.

11

Broadcast update mode. This mode has two functions. In broadcast mode, DAC5574 responds

regardless of local address matching, and channel selection becomes irrelevant as all channels update.

address (1001 0000).

If Sel1=0

All four channels are updated with the contents of their temporary register

data.

If Sel1=1

All four channels are updated with the MS-BYTE and LS-BYTE data or

powerdown.

Sel1

Buff Sel1 Bit

Channel Select Bits

Sel0

Buff Sel0 Bit

00

Channel A

01

Channel B

10

Channel C

11

Channel D

PD0

Power Down Flag

0

Normal operation

1

Power-down flag (MSB7 and MSB6 indicate a power-down operation, as shown in Table 2).

14