SM5956A

SEIKO NPC CORPORATION —16

MCU Interface (MDT, MCK, MLE pins)

The SM5956A has a 3-wire serial MCU interface that is used to set the digital audio interface channel status

data.

Command format

The commands from a microcontroller are input using the data input (MDT), bit clock (MCK), and load signal

(MLE) inputs in bit serial format.

Register table

I

Address: 0/H

Note. Each flag operates using logic-OR with its corresponding external input pin of the same name. If only the MCU interface is used for control, all the

pins corresponding to the flags must be set to their inactive level. When the flags are set to their default level, control using external pins is enabled.

I

Address: 1/H

Note. This LSI can accept 4 type category codes shown in the table.

Write command format

Bit

Flag name

Description

Default

D11

Not used

Set to 0 for normal operation

0

D10

Not used

Set to 0 for normal operation

0

D9

Not used

Set to 0 for normal operation

0

D8

Not used

Set to 0 for normal operation

0

D7

Not used

Set to 0 for normal operation

0

D6

DMUTEN

Direct mute flag

1

D5

THROUN

Through mode flag

1

D4

SLAVEN

Slave mode flag

1

D3

OEDITON

DIT output enable flag

1

D2

DEEMN

Deemphasis select flag

1

D1

FS1

Deemphasis frequency select flag 1

0

D0

FS0

Deemphasis frequency select flag 0

0

Bit

Flag name

Description

Default

D11

CNTL0

Channel status bit 0

0

D10

CNTL1

Channel status bit 1

0

D9

CNTL2

Channel status bit 2. COPY flag

0

D8

CNTL3

Channel status bit 3. EMP flag

0

D7

CATGY0

Category code set flag 0

(CATGY1, CATGY0) = category

(0, 0) = “100 0000L” (CD)

(0, 1) = “100 1100L” (DVD)

(1, 0) = “100 0100L” (VCD)

(1, 1) = “010 1100L” (SRC)

0

D6

CATGY1

Category code set flag 1

0

D5

Not used

0

D4

LBIT

Channel status bit 15

0

D3

CFS1

Channel status bit 24

0

D2

CFS2

Channel status bit 25

0

D1

CP1

Channel status bit 28

0

D0

CP2

Channel status bit 29

0

A3 A2 A1 A0 D11D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

Data 12bit

Address 4bit

MDT

MCK

MLE