Maxim DS33Z41 specifications Pattern Monitoring, Pattern Generation, Error Insertion

DS33Z41 Quad IMUX Ethernet Mapper

Figure 8-13. Repetitive Pattern Synchronization State Diagram

Sync

r

o

r

s

r

t

e

u

o

it

h

w

it s

2

b

3

6

o f

6 4

b i t s

w

i t h

e r r o r s

1 bit error

VerifyMatch

Pattern Matches

8.15.4 Pattern Monitoring

Pattern monitoring monitors the incoming data stream for Out Of Synchronization (OOS) condition, bit errors, and counts the incoming bits. An OOS condition is declared when the synchronization state machine is not in the “Sync” state. An OOS condition is terminated when the synchronization state machine is in the “Sync” state.

Bit errors are determined by comparing the incoming data stream bit to the receive pattern generator output. If they do not match, a bit error is declared, and the bit error and bit counts are incremented. If they match, only the bit count is incremented. The bit count and bit error count are not incremented when an OOS condition exists.

8.15.5 Pattern Generation

Pattern Generation generates the outgoing test pattern, and passes it onto Error Insertion. The transmit pattern generator is a 32-bit shift register that shifts data from the least significant bit (LSB) or bit 1 to the most significant bit (MSB) or bit 32. The input to bit 1 is the feedback. For a PRBS pattern (generating polynomial xn + xy + 1), the feedback is an XOR of bit n and bit y. For a repetitive pattern (length n), the feedback is bit n. The values for n and y are individually programmable. The output of the receive pattern generator is the feedback. If QRSS is enabled, the feedback is an XOR of bits 17 and 20, and the output is forced to one if the next 14 bits are all zeros. QRSS is programmable (on or off). For PRBS and QRSS patterns, the feedback is forced to one if bits 1 through 31 are all zeros. When a new pattern is loaded, the pattern generator is loaded with a pattern value before pattern generation starts. The pattern value is programmable (0 – 2n - 1). When PRBS and QRSS patterns are generated the seed value is all ones.

8.15.5.1 Error Insertion

Error insertion inserts errors into the outgoing pattern data stream. Errors are inserted one at a time Single bit error insertion can be initiated from the microprocessor interface. If pattern inversion is enabled, the data stream is inverted before the overhead/stuff bits are inserted. Pattern inversion is programmable (on or off).

50 of 167