NICON (NICAM Control)

Address

: 09

Type

: R/W

Reset

: 0000 0000

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

DIF-POL

0

TSCTRL

ECT

MAE

0

0

DIF-POL

: controls the polarity of the Q channel in the DQPSK decoder. Its default value is correct for

Nicam B/G/L and so does not need to be changed.

TSCTRL

: These two bits are programmed to chose the decision mode for the zweiton detector as

following :

00

01

10

11

:

:

:

:

2 decisions with 1024 samples accumulation

3 decisions with 1024 samples accumulation

2 decisions with 2048 samples accumulation

3 decisions with 2048 samples accumulation

ECT

: bit error rate counting time : 0 = 128ms, 1 = 64ms

MAE

: max allowed errors : 0 = 511, 1 = 255

Bits 2 and 3 adjust the bit error rate (approximate) at which the Nicam decoder mutes; a fixed

hysteresis is provided so that the decoder will unmute only when the BER has dropped to

one quarter of that for muting :

ECT

MAE

BER Muting Threshold

0

0

1 in 112

0

1

1 in 224

10

1 in 56

1

1

1 in 112

ERR-COUNT (Nicam Error Counter)

Address

: 0A

Type

: R

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

ERROR

Error Signals Count (averaged over time ECT above)

The value in this register, updated every 64ms or 128ms, gives an indication of the Nicam bit error rate. It

can therefore be used to mute the decoder at an error rate below 1 in 56 (=FF if ECT= 64ms).

PROGRAMMING THE DEVICE (continued)

STV8203

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