Datasheet

Integrated I/O (IIO) Configuration Registers
278 Intel
®
Xeon
®
Processor E7-2800/4800/8800 v2 Product Family
Datasheet Volume Two: Functional Description, February 2014
14.2.109 LN[0:3]EQ
Lane 0 through Lane 3 Equalization Control
Type: CFG PortID: N/A
Bus: 0 Device: 2Function:0-3
Bus: 0 Device: 3Function:0-3
Offset: 0x25c, 0x25e, 0x260, 0x262
Bit Attr Default Description
15:15 RV - Reserved.
14:12 RW_O 0x7
dnrxpreset:
Downstream Component Receiver Preset Hint
Receiver Preset Hint for Downstream Component with the following
encoding. The Upstream component must pass on this value in the EQ
TS2’es.
000b: -6 dB
001b: -7 dB
010b: -8 dB
011b: -9 dB
100b: -10 dB
101b: -11 dB
110b: -12 dB
111b: Reserved
For a Downstream Component, this field reflects the latest Receiver Preset
value requested from the Upstream Component on Lane 0. The default value
is 111b.
11:8 RW_O 0x8
dntxpreset:
Downstream Component Transmitter Preset
Transmitter Preset for Downstream Component with the following encoding.
The Upstream component must pass on this value in the EQ TS2’es.
0000b: -6.0 dB for deemphasis, 0 dB for preshoot
0001b: -3.5 dB for deemphasis, 0 dB for preshoot
0010b: -4.5 dB for deemphasis, 0 dB for preshoot
0011b: -2.5 dB for deemphasis, 0 dB for preshoot
0100b: 0 dB for deemphasis, 0 dB for preshoot
0101b: 0 dB for deemphasis, 2.0 dB for preshoot
0110b: 0 dB for deemphasis, 2.5 dB for preshoot
0111b: -6.0 dB for deemphasis, 3.5 dB for preshoot
1000b: -3.5 dB for deemphasis, 3.5 dB for preshoot
1001b: 0 dB for deemphasis, 3.5 dB for preshoot
others: reserved
For a Downstream Component, this field reflects the latest Transmitter
Preset requested from the Upstream Component on Lane N.
Notes:
1) P0, P1, P4, P7, P8 and P9 are used for normal situation.
2) P2, P3, P5 and P6 are used only for validation purpose, such as to run
PCIe* Tx CEM test.
7:7 RV - Reserved.