SBASAQ9 October 2023 ADC12QJ1600-SEP
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
The PRBS test modes bypass the JESD204C transport layer and link layer and are therefore neither scrambled nor encoded. These test modes produce pseudo-random bit streams that comply with the ITU-T O.150 specification. These bit streams are used with lab test equipment or logic devices that can self-synchronize to the bit pattern. The initial phase of the pattern is not defined since the receiver self synchronizes.
The sequences are defined by a recursive equation. For example, Equation 12 defines the PRBS7 sequence.
where
Table 6-34 lists equations and sequence lengths for the available PRBS test modes where ⊕ is the XOR operation and y[n] represents bit n in the PRBS sequence. The initial phase of the pattern is unique for each lane.
PRBS TEST MODE | SEQUENCE | SEQUENCE LENGTH (bits) |
---|---|---|
PRBS7 | y[n] = y[n – 6]⊕y[n – 7] | 127 |
PRBS9 | y[n] = y[n – 5]⊕y[n – 9] | 511 |
PRBS15 | y[n] = y[n – 14]⊕y[n – 15] | 32,767 |
PRBS23 | y[n] = y[n – 18]⊕y[n – 23] | 8,388,607 |
PRBS31 | y[n] = y[n – 28]⊕y[n – 31] | 2,147,483,647 |