SERIAL

Select Serial or Parallel Mode

SERIAL

Opcode:

07

00000111

Synopsis

SERIAL defines the data path, i.e. either serial or parallel.

Parameters

Field

Byte

Pos.

Value

Definition

TX_SDATA

1

0

0*

1

Use serial link for Tx Data

Use parallel link for Tx Data

RX_SDATA

1

1

0*

1

Use only serial link for Rx Data

Use also parallel link for Rx Data

Notes :

The received Bits always go to the output pin RXD, even when the RX_SDATA bit is set.

SETGN

Set Output Gain

SETGN

Opcode:

02

00000010

Synopsis

SETGN is a command which sets the scaling factor of the transmit samples. It is used for

setting the output level or for setting the level of the tone generators. The gain value is

given in the form of a 2’s complement 16-bit value.

Parameters

Field

Byte

Pos.

Value

Definition

GAIN_L

1

7..0

range FF*

Low byte of the 16-bit gain value

GAIN_H

2

7..0

range 7F*

High byte of the 16-bit gain value

Example

Gain (dB)

Gain (Hex)

Gain (dB)

Gain (Hex)

Gain (dB)

Gain (Hex)

0

7FFF

-5

47FA

-10

287A

-1

7214

-6

4026

-11

2413

-2

65AC

-7

392C

-12

2026

-3

5A9D

-8

32F5

-13

1CA7

-4

50C3

-9

2D6A

-14

198A

SLEEP

Turn to Sleep Mode

SLEEP

Opcode:

03

00000011

Synopsis

SLEEP is used to force the ST75C520 to turn to low power mode.

Parameter

Non parametric command.

Notes :

When receiving this command the ST75C520 will stop processing and so cannot have the regular handshake protocol.

It does not increment the COMACK, neither generate an Interrupt.

STOP

FAX Stop Transmitter

STOP

Opcode:

25

00100101

Synopsis

STOP is used, in FAX Modes, to force the ST75C520 to turn off the transmitter in

accordance with the corresponding ITU-T V.33/V.17/V.29/V.27recommendation.

Parameter

Non parametric command.

Notes :

When receiving this command the ST75C520 will stop sending regular Data. In parallel mode this command must be

preceded by a XMIT Stop command. In parallel mode the ST75C520 will wait until all the transmit buffers are sent before

starting the Stop sequence.

ST75C520

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