User Manual

DS2172

031197 8/20

PT3 PTR.3 Polynomial Tap Bit 3.

PT2 PTR.2 Polynomial Tap Bit 2.

PT1 PTR.1 Polynomial Tap Bit 1.

PT0 PTR.0 Polynomial Tap Bit 0.

6.0 PATTERN CONTROL REGISTER

The Pattern Control Register (PCR) is used to configure

the operating parameters of the DS2172 and to control

the patterns being generated and received. Also the

PCR is used to control the pattern synchronizer and the

error and bit counters.

PCR: PATTERN CONTROL REGISTER (Address=06 Hex)

(MSB) (LSB)

TL QRSS PS LC RL SYNCE RESYNC LPBK

SYMBOL POSITION NAME AND DESCRIPTION

TL PCR.7 Transmit Load. A low to high transition loads the pattern generator with

the contents of the Pattern Set Registers. PCR.7 is logically ORed with the

input pin TL. Must be cleared and set again for subsequent loads.

QRSS PCR.6 Zero Suppression Select. Forces a “one” into the pattern whenever the

next 14 bit positions are all “zeros”. Should only be set when using the

QRSS pattern.

0 = Zero suppression disabled

1 = Zero suppression enabled

PS PCR.5 Pattern Select.

0 = Repetitive Pattern

1 = Pseudorandom Pattern

LC PCR.4 Latch Count Registers. A low to high transition latches the bit and error

counts into the user accessible registers BCR and BECR and clears the

internal register count. PCR.4 is logically OR’ed with input pin LC. Must be

cleared and set again for subsequent loads.

RL PCR.3 Receive Data Load. A transition from low to high loads the previous 32 bits

of data received at RDATA into the Pattern Receive Registers (PRR).

PCR.3 is logically OR’ed with input pin RL. Must be cleared and set again

for subsequent latches.

SYNCE PCR.2 SYNC Enable.

0 = auto resync is enabled.

1 = auto resync is disabled.

RESYNC PCR.1 Initiate Manual Resync Process. A low to high transition will force the

DS2172 to resynchronize to the incoming pattern at RDATA. Must be

cleared and set again for a subsequent resync.

LPBK PCR.0 T ransmit/Receive Loopback Select. When enabled, the RDA T A input is

disabled; TDATA continues to output data as normal. See Figure 1.

0 = loopback disabled

1 = loopback enabled