DS125BR820 Datasheet, PDF (37/62 Pages) Texas Instruments – Low-Power 12.5 Gbps 8-Channel Linear Repeater

www.ti.com
DS125BR820
SNLS491B – JULY 2014 – REVISED FEBRUARY 2015
Address
Register
Name
0x3B
CH6 - CHA_2
VOD
0x3C
CH6 - CHA_2
VOD_DB
0x3D
CH6 - CHA_2
SD_TH
0x3E-
0x3F
Reserved
Table 9. SMBus Slave Mode Register Map (continued)
Bit
Field
Type Default
EEPROM
Reg Bit
Description
7
Short Circuit
Protection
Yes
1 = Enable the short circuit protection
0 = Disable the short circuit protection
6:3 Reserved
Yes Set bits to 0101'b
R/W 0xAD
2:0 VOD Control
OUTA_2 VOD Control: VOD / VID Ratio
000'b = 0.57
001'b = 0.65
010'b = 0.71
Yes 011'b = 0.77
100'b = 0.83
101'b = 0.90 (default)
110'b = 1.00 (recommended)
111'b = 1.04
7 RXDET Status
R
Observation bit for RXDET CH6 - CHA_2
1 = Input 50 Ω terminated to VDD
0 = Input is Hi-Z
6:5 Reserved
Set bits to 0
4:3 Reserved
Set bits to 0
0x02
2:0
VOD_DB ^R/W
Control
OUTA_2 VOD_DB Control
000'b = 0 dB (recommended)
001'b = –1.5 dB
010'b = –3.5 dB (default)
011'b = –5 dB
Yes
100'b = –6 dB
101'b = –8 dB
110'b = –9 dB
111'b = –12 dB
Note: Changing VOD_DB bits effectively lowers the
output VOD dynamic range by a factor of the
corresponding amount of dB reduction.
7
Reserved
Yes Set bit to 0
6:4 Reserved
Set bits to 0
Signal Detect
3:2 Status Assert
Threshold
R/W 0x00
Status Assert threshold (1010 pattern 12 Gbps)
00'b = 50 mVp-p (default)
01'b = 40 mVp-p
Yes 10'b = 75 mVp-p
11'b = 58 mVp-p
Note: Override SD_TH pin and enable register control
via Reg 0x08[6]
Signal Detect
1:0
Status
De-assert
Threshold
Status De-assert threshold (1010 pattern 12 Gbps)
00'b = 37 mVp-p (default)
01'b = 22 mVp-p
Yes 10'b = 55 mVp-p
11'b = 45 mVp-p
Note: Override SD_TH pin and enable register control
via Reg 0x08[6]
7:0 Reserved R/W 0x00
Set bits to 0
Copyright © 2014–2015, Texas Instruments Incorporated
Submit Documentation Feedback
37