M116 INSTRUCTION SET (continued)

INSTRUCTION 4: OVERFLOW INFORMATION

Two bytes are needed to know the status of all 10 conferences: C/D = 0 reads the first byte (first 8 con-

ferences) and C/D = 1 reads the second byte (the last 2 conferences). A conference is in overflow when

the corresponding bit is high.

Instruction 4 Format

Control Signal

Data Bus

CS

RD

C/D

WR

D7

D6

D5

D4

D3

D2

D1

D0

0

0

0

1

CF8

CF7

CF6

CF5

CF4

CF3

CF2

CF1

0

0

1

1

XX

XXXX

CF10

CF9

CF10 – CF1: Conference in overflow when high.

nb: as long as RD remains low, the overflow status of the conference selected by C/D can be monitored

in real time.

INSTRUCTION 5: OPERATING MODE

The single byte needed contains the Extra bit (D6), the format bits F1–F0 (D5–D4) and the opcode

(0101).

The E bit must be E = 1 when the PCM frame contains a number of bit multiple of eight plus on bit (ex.

PCM frame at 1544Kbit/s). Normally E = 0. The bits F1–F0 select the kinds of PCM format byte accord-

ing table 1. After Reset the default values corresponds to F1 = 0, F0 = 1 if A–law is selected and F1 = 1,

F0 = 1 if Mu–law is selected. All channels must be disconnected when the Operating Mode Instruction is

sent. They must remain disconnected for at least two time frames after the instruction was sent.

We recommende to use this instruction right after the RESET (see pin RESET decription).

Instruction 5 Format

Control Signal

Data Bus

CS

RD

C/D

WR

D7

D6

D5

D4

D3

D2

D1

D0

01

10

X

E

F1

F0

0

101

E: Extra bit insertion (active when E = 1)

F1 – F0: PCM byte Format selection (see also table 1)

00 = no bit inverted

01 = even bit (B0–B2–B4–B6) inverted

10 = odd bit (B1–B3–B5) inverted

11 = all bit (B0–B1–B2–B3–B4–B5–B6)inverted

INSTRUCTION 6: STATUS

Three bytes are needed:

1) The first byte contains the number of the channel;

2) The second byte contains the opcode (0110);

3) By a reding cycle you extract from the third byte the information about the operating mode of the

channel (no connection or transparent mode or number of the conference, bits D4–D7); the attenuation

(D2–D3) and noise suppression values (D0–D1) eventually inserted.

This reading cycle must be executed at least one frame after the end of the opcode writing cycle.

Instruction 6 Format

Control Signal

Data Bus

CS

RD

C/D

WR

D7

D6

D5

D4

D3

D2

D1

D0

0

1

0

0

X

X

X

C4C3

C2C1C0

01

10

X

X

X

X

0

110

0

0

1

1

P3

P2

P1

P0

A1

A0

T1

T0

P3–P0: channel mode operation information

0000 = no connection

1111 = transparent mode

1010 – 0001 = conference mode

P3–P0 give the number of the conferenc

nb: the instruction 6 enables the dat bus to read

the status until reset by C/D = 0 and WR = 1.

M34116

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