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Registers
1409
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Serial ATA (SATA) Controller
Table 28-38. Port PHY Control Register (P0PHYCR) Field Descriptions (continued)
Bit
Field
Value
Description
17
TXINVPAIR
Transmitter Invert Polarity. Inverts the polarity of TXP0 and TXN
16-13
RXEQ
0-Fh
Receiver Equalizer. Enables and configures the adaptive equalizer to compensate for loss in the
transmission media.
Low Frequency
Gain
Zero Frequency
0
Maximum
—
1h
Adaptive
2h-7h
Reserved
8h
Adaptive
365 MHz
9h
Adaptive
275 MHz
Ah
Adaptive
195 MHz
Bh
Adaptive
140 MHz
Ch
Adaptive
105 MHz
Dh
Adaptive
75 MHz
Eh
Adaptive
55 MHz
Fh
Adaptive
50 MHz
12-10
RXCDR
0-7h
Receiver Clock/data Recovery. Configures the clock/data recovery algorithm.
0
First order, threshold of 1. Phase offset tracking up to ±312 ppm. Suitable for use in asynchronous
systems with low frequency offset.
1h
First order, threshold of 16. Phase offset tracking up to ±260 ppm in the presence of ..10101010..
training pattern, or ±195 ppm in the presence of 2
7
PRBS. Suitable for use in synchronous systems.
Offers superior rejection of random jitter, but is less responsive to systematic variation such as
sinusoidal jitter.
2h
Second order, high precision, threshold of 1. Highest precision frequency offset matching but
relatively poor response to changes in frequency offset, and long lock time. Suitable for use in
systems with fixed frequency offset.
3h
Second order, high precision, threshold of 16. Highest precision frequency offset matching but
poorest response to changes in frequency offset, and longest lock time. Suitable for use in systems
with fixed frequency offset and low systematic variation.
4h
Second order, low precision, threshold of 1. Best response to changes in frequency offset and
fastest lock time, but lowest precision frequency offset matching. Suitable for use in systems with
spread spectrum clocking.
5h
Second order, low precision, threshold of 16. Good response to changes in frequency offset and
fast lock time, but low precision frequency offset matching. Suitable for use in systems with spread
spectrum clocking.
6h
First order, threshold of 1 with fast lock. Phase offset tracking up to ±1560 ppm in the presence
of ..10101010.. training pattern; and ±312 ppm, otherwise.
7h
Second order, low precision with fast lock. As per setting 100, but with improved response to
changes in frequency offset when not close to lock.
9-8
RXTERM
0-3h
Receiver Termination. Selects input termination options suitable for a variety of AC or DC coupled
scenarios.
0
Common point set to V
SSA
. This configuration is for applications that are AC coupled at the receive
end that require a 0V common mode. Common mode termination is direct to V
SSA
.
1h
Common point set to 0.8 V
DDA
. This configuration is for AC coupled systems. The transmitter has no
effect on the receiver common mode, which is set to optimize the input sensitivity of the receiver.
Common mode termination is via a 50 pF capacitor to V
SSA
. This mode is probably not used for
SATA.
2h
Common point set to 0.2 V
DDA
. This configuration is for applications (DC coupled or AC coupled at
the transmit end) that require a low common mode. Common mode termination is via a 50 pF
capacitor to V
SSA
.
3h
Common point floating, wide common mode range. This configuration utilizes the internal AC
coupled level shifters to support a wide common mode range, and it therefore requires DC
balanced coding. It can also be used to achieve high single ended impedance. This mode is
probably not used for SATA.
7
RXINVPAIR
0-1
Receiver Invert Polarity. Inverts the polarity of RXP0 and RXN.