REV. 0

AD1833A

–16–

Packed Mode 128

In Packed Mode 128, all six data channels are packed into one

sample interval on one data pin. The BCLK runs at 128

therefore, there are 128 BCLK periods in each sample interval.

Each sample interval is broken into eight time slots: six slots of

20 BCLK and two of 4 BCLK. In this mode, the data length is

restricted to a maximum of 20 bits. The three left channels are

written first, MSB first, and the data is written on the falling

edge of BCLK. After the three left channels are written, there is

a space of four BCLK, and then the three right channels are writ-

ten. The L/

RCLK defines the left and right data transmission; it

is high for the three left channels and low for the three right channels.

Packed Mode 256

In Packed Mode 256, all six data channels are packed into one

sample interval on one data pin. The BCLK runs at 256

therefore, there are 256 BCLK periods in each sample interval, and

each sample interval is broken into eight time slots of 32 BCLK

each. The data length can be 16, 20, or 24 bits. The three left

channels are written first, MSB first, and the data is written on the

falling edge of BCLK with a one BCLK period delay from the

start of the slot. After the three left channels are written, there is

a space of 32 BCLK, and then the three right channels are written.

The

L/RCLK defines the left and right data transmission; it is

low for the three left channels and high for the three right channels.

SLOT 1

LEFT 0

SLOT 2

LEFT 1

SLOT 3

LEFT 2

BLANK SLOT

4 SCLK

SLOT 4

RIGHT 0

SLOT 5

RIGHT 1

SLOT 6

RIGHT 2

BLANK SLOT

4 SCLK

DATA

20-BIT DATA

16-BIT DATA

BCLK

BCLK

MSB

–1

MSB

–2

MSB

–3

MSB

–4

MSB

–1

MSB

–2

MSB

–3

MSB

–4

LSB

+4

LSB

+3

LSB

+2

LSB

+1

MSB

LSB

LSB

MSB

L/

RCLK

Figure 11. Packed Mode 128

SLOT 1

LEFT 0

SLOT 2

LEFT 1

SLOT 3

LEFT 2

SLOT 4

RIGHT 0

SLOT 5

RIGHT 1

SLOT 6

RIGHT 2

20-BIT DATA

24-BIT DATA

16-BIT DATA

BCLK

MSB

–1

MSB

–2

MSB

–3

MSB

–4

MSB

–1

MSB

–2

MSB

–3

MSB

–4

LSB

+8

LSB

+7

LSB

+6

LSB

+5

LSB

+4

LSB

+3

LSB

+2

LSB

+1

LSB

+4

LSB

+3

LSB

+2

LSB

+1

MSB

LSB

LSB

LSB

MSB

MSB

–1

MSB

–2

MSB

–3

MSB

–4

MSB

DATA

BCLK

L/RCLK

Figure 12. Packed Mode 256