DS80PCI402 Datasheet, PDF (27/39 Pages) Texas Instruments – 2.5 Gbps / 5.0 Gbps / 8.0 Gbps 4 Lane PCI Express Repeater with Equalization and De-Emphasis

0x26
CH3 - CHB3
DEM
0x27
CH3 - CHB3
IDLE Threshold
0x2B
CH4 - CHA0
IDLE, RXDET
0x2C
CH4 - CHA0
EQ
7
RXDET STATUS R 0x02 Observation bit for RXDET CH3 - CHB3.
1: RX = detected
0: RX = not detected
6:5 RATE_DET
R
STATUS
Observation bit for RATE_DET CH3 - CHB3.
00: GEN1 (2.5G)
01: GEN2 (5G)
11: GEN3 (8G)
4:3 Reserved
R/W
Set bits to 0.
2:0 DEM Control
R/W
OB3 DEM Control
000: 0 dB
001: –1.5 dB
010: –3.5 dB (default)
011: –5 dB
100: –6 dB
101: –8 dB
110: –9 dB
111: –12 dB
7:4 Reserved
R/W 0x00 Set bits to 0.
3:2 IDLE thd
De-assert threshold
00 = 110 mVp-p (default)
01 = 100 mVp-p
10 = 150 mVp-p
11 = 130 mVp-p
Note: override the SD_TH pin.
1:0 IDLE tha
Assert threshold
00 = 180 mVp-p (default)
01 = 160 mVp-p
10 = 210 mVp-p
11 = 190 mVp-p
Note: override the SD_TH pin.
7:6 Reserved
R/W 0x00 Set bits to 0.
5
IDLE_AUTO
1: Automatic IDLE detect
0: Allow IDLE_SEL control in bit 4
Note: override IDLE control.
4
IDLE_SEL
1: Output is MUTED (electrical idle)
0: Output is ON
Note: override IDLE control.
3:2 RXDET
00: Input is high-z impedance
01: Auto RX-Detect,
outputs test every 12 ms for 600 ms (50 times)
then stops; termination is high-z until detection;
once detected input termination is 50 Ω
10: Auto RX-Detect,
outputs test every 12 ms until detection occurs;
termination is high-z until detection; once
detected input termination is 50 Ω
11: Input is 50 Ω
Note: override RXDET pin.
1:0 Reserved
Set bits to 0.
7:0 EQ Control
R/W 0x2F
IA0 EQ Control - total of 256 levels.
See Table 2: Equalizer Settings.
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