DP83847 datasheet(43/60 Pages) NSC

43 / 60 page

www.national.com

Table 23. CD Test Register (CDCTRL), Address 0x1B

Bit

Bit Name

Default

Description

CD_ENABLE

1, RW

CD Enable:

1 = CD Enabled - power-down mode, outputs high impedance.

0 = CD Disabled.

DCDCOMP

0, RW

Duty Cycle Distortion Compensation:

1 = Increases the amount of DCD compensation.

FIL_TTL

0, RW

Waveshaper Current Source Test:

To check ability of waveshaper current sources to switch on/off.

1 = Test mode; waveshaping is done, but the output is a square

wave. All sources are either on or off.

0 = Normal mode; sinusoidal.

RESERVED

none, RW

Reserved: This bit should be written with a 0 if write access is re-

quired on this register.

RISETIME

Strap, RW

CD Rise Time Control:

RESERVED

none, RW

Reserved: This bit should be written with a 0 if write access is re-

quired on this register.

FALLTIME

Strap, RW

CD Fall Time Control:

CDTESTEN

0, RW

CD Test Mode Enable:

1 = Enable CD test mode - differs based on speed of operation

(10/100Mb).

0 = Normal operation.

7:5

RESERVED[2:0]

000, RW

RESERVED:

Must be zero.

CDPATTEN_10

0, RW

CD Pattern Enable for 10meg:

1 = Enabled.

0 = Disabled.

CDPATTEN_100

0, RW

CD Pattern Enable for 100meg:

1 = Enabled.

0 = Disabled.

10MEG_PATT_GAP

0, RW

Defines gap between data or NLP test sequences:

1 = 15

µs.

0 = 10

µs.

1:0

CDPATTSEL[1:0]

00, RW

CD Pattern Select[1:0]:

If CDPATTEN_100 = 1:

00 = All 0’s (True quiet)

01 = All 1’s

10 = 2 1’s, 2 0’s repeating pattern

11 = 14 1’s, 6 0’s repeating pattern

If CDPATTEN_10 = 1:

00 = Data, EOP0 sequence

01 = Data, EOP1 sequence

10 = NLPs

11 = Constant Manchester 1s (10mhz sine wave) for harmonic dis-

tortion testing.

DP83847 датащи(PDF) 43 Page - National Semiconductor (TI)

DP83847 датащи(HTML) 43 Page - National Semiconductor (TI)

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

датащи скачать

ссылки URL