User Guide

Table Of Contents
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SRIO Functional Description
Table 9. EQ Bits
CFGRX[22:19] Low Freq Gain Zero Freq (at e
28
(min))
0000 Maximum -
0001 Adaptive Adaptive
001x Reserved
01xx Reserved
1000 Adaptive 1084MHz
1001 805MHz
1010 573MHz
1011 402MHz
1100 304MHz
1101 216MHz
1110 156MHz
1111 135MHz
2.3.2.3 Enabling the Transmitter
To enable a transmitter for serialization, the ENTX bit of the associated SERDES_CFGTX n_CNTL
registers (0x110 0x10c) must be set high. When ENTX is low, all digital circuitry within the transmitter
will be disabled, and clocks will be gated off, with the exception of the transmit clock (TXBCLK[ n]) output,
which will continue to operate normally. All current sources within the transmitter will be fully powered
down, with the exception of the CML driver, which will remain powered up if boundary scan is selected.
Table 10. Bits of SERDES_CFGTX n_CNTL Registers
Bit Field Value Description
31:17 Reserved Reserved.
16 ENFTP Enable fixed TXBCLKIN n phase. Enables fixed phase relationship of TXBCLKIN n with respect to
TXBCLK n.
0 Arbitrary phase. No required phase relationship between TXBCLKIN n and TXBCLK n.
1 Fixed phase. Requires direct connection of TXBCLK n to TXBCLKIN n using a minimum length
net without buffers.
15:12 DE De-emphasis. Selects one of 15 output de-emphasis settings from 4.76 to 71.42%. See
Table 12 .
11:9 SWING Output swing. Selects one of 8 output amplitude settings between 125 and 1250mV
dfpp
. See
Table 11 .
8 CM Common mode. Adjusts the common mode to suit the termination at the attached receiver.
0 Normal common mode. Common mode not adjusted.
1 Raised common mode. Common mode raised by 5% of e
54
.
7 INVPAIR Invert polarity. Inverts polarity of TXP n and TXNn.
0 Normal polarity. TXP n considered to be positive data and TXN n negative.
1 Inverted polarity. TXP n considered to be negative data and TXN n positive.
6:5 RATE Operating rate. Selects full, half or quarter rate operation.
00 Full rate. Two data samples taken per PLL output clock cycle.
01 Half rate. One data sample taken per PLL output clock cycle.
10 Quarter rate. One data sample taken every two PLL output clock cycles.
11 Reserved
30 Serial RapidIO (SRIO) SPRU976 March 2006
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