User Guide

Table Of Contents
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SRIO Functional Description
Here is the frequency range versus MPY:
Table 7. Frequency Range versus MPY
MPY RIOCLK and RIOCLK Line Rate Range (Gbps)
Range (MHz) Full Half Quarter
4x 250 - 425 2 - 3.4 1 - 1.7 0.5 - 0.85
5x 200 - 425 2 - 4.25 1 - 2.125 0.5 - 1.0625
6x 167 - 354.167 2 - 4.25 1 - 2.125 0.5 - 1.0625
8x 125 - 265.625 2 - 4.25 1 - 2.125 0.5 - 1.0625
10x 100 - 212.5 2 - 4.25 1 - 2.125 0.5 - 1.0625
12x 83.33 - 177.08 2 - 4.25 1 - 2.125 0.5 - 1.0625
12.5x 80 - 170 2 - 4.25 1 - 2.125 0.5 - 1.0625
15x 66.67 - 141.67 2 - 4.25 1 - 2.125 0.5 - 1.0625
20x 50 - 106.25 2 - 4.25 1 - 2.125 0.5 - 1.0625
25x 40 - 85 2 - 4.25 1 - 2.125 0.5 - 1.0625
50x 25 - 42.5 2.5 - 4.25 1.25 - 2.125 0.625 - 1.0625
60x 25 - 35.42 3 - 4.25 1.5 - 2.125 0.75 - 1.0625
2.3.2.2 Enabling the Receiver
To enable a receiver for deserialization, the ENRX bit of the associated SERDES_CFGRX n_CNTL
registers (0x100-0x10c) must be set high.
When ENRX is low, all digital circuitry within the receiver will be disabled, and clocks will be gated off. All
current sources within the receiver will be fully powered down, with the exception of those associated with
the loss of signal detector and IEEE1149.6 boundary scan comparators. Loss of signal power down is
independently controlled via the LOS bits of SERDES_CFGRX n_CNTL.
Table 8. Bits of SERDES_CFGRX n_CNTL Registers
Bit Field Value Description
31:26 Reserved Reserved.
25 Reserved Reserved, keep as zero during writes to this register.
24 Reserved Reserved, keep as zero during writes to this register.
23 Reserved Reserved.
22:19 EQ Equalizer. Enables and configures the adaptive equalizer to compensate for loss in the
transmission media. For values, see Table 9 .
18:16 CDR Clock/data recovery. Configures the clock/data recovery algorithm.
000 First order. Phase offset tracking up to ± 488 ppm.
001 Second order. 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.
010 Second order. Medium precision frequency offset matching, frequency offset change response
and lock time.
011 Second order. 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.
100 First order with fast lock. Phase offset tracking up to ± 1953 ppm in the presence of ..10101010..
training pattern, and ± 448 ppm otherwise.
101 Second order with fast lock. As per setting 001, but with improved response to changes in
frequency offset when not close to lock.
110 Second order with fast lock. As per setting 010, but with improved response to changes in
frequency offset when not close to lock.
111 Second order with fast lock. As per setting 011, but with improved response to changes in
frequency offset when not close to lock.
28 Serial RapidIO (SRIO) SPRU976 March 2006
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