Rainbow Electronics DS3170 - Manual (Page 152)

DS3170 DS3/E3 Single-Chip Transceiver
152 of 233
11.5.2 Receive Side Line Encoder/Decoder Register Map
The receive side utilizes six registers.
Table 11-15. Receive Side B3ZS/HDB3 Line Encoder/Decoder Register Map
Address
Register
Register Description
090h LINE.RCR Line Receive Control Register
092h -- Unused
094h LINE.RSR Line Receive Status Register
096h LINE.RSRL Line Receive Status Register Latched
098h LINE.RSRIE Line Receive Status Register Interrupt Enable
09Ah -- Unused
09Ch LINE.RBPVCR Line Receive Bipolar Violation Count Register
09Eh LINE.REXZCR Line Receive Excessive Zero Count Register
11.5.2.1 Register Bit Descriptions
Register Name:
LINE.RCR
Register Description: Line Receive Control Register
Register Address: (0.2.4.6)90h
Bit
# 15 14 13 12 11 10 9 8
Name -- -- -- -- -- -- -- --
Default 0 0 0 0 0 0 0 0
Bit
# 7 6 5 4 3 2 1 0
Name -- -- -- -- E3CVE REZSF RDZSF RZSD
Default 0 0 0 0 0 0 0 0
Bit 2: E3 Code Violation Enable (E3CVE) – When 0, the bipolar violation count will be a count of bipolar
violations. When 1, the bipolar violation count will be a count of E3 line coding violations. Note: E3 line coding
violations are defined as consecutive bipolar violations of the same polarity in ITU O.161. This bit is ignored in
B3ZS mode.
Bit 2: Receive BPV Error Detection Zero Suppression Code Format (REZSF) – When 0, BPV error detection
detects a B3ZS signature if a zero is followed by a bipolar violation (BPV), and an HDB3 signature if two zeros are
followed by a BPV. When 1, BPV error detection detects a B3ZS signature if a zero is followed by a BPV that has
the opposite polarity of the BPV in the previous B3ZS signature, and an HDB3 signature if two zeros are followed
by a BPV that has the opposite polarity of the BPV in the previous HDB3 signature. Note: Immediately after a reset,
this bit is ignored. The first B3ZS signature is defined as a zero followed by a BPV, and the first HDB3 signature is
defined as two zeros followed by a BPV. All subsequent B3ZS/HDB3 signatures will be determined by the setting of
this bit.
Note: The default setting (REZSF = 0) conforms to ITU O.162. The default setting may falsely decode actual BPVs
that are not codewords. It is recommended that REZSF be set to one for most applications. This setting is more
robust to accurately detect codewords.
Bit 1: Receive Zero Suppression Decoding Zero Suppression Code Format (RDZSF) – When 0, zero
suppression decoding detects a B3ZS signature if a zero is followed by a bipolar violation (BPV), and an HDB3
signature if two zeros are followed by a BPV. When 1, zero suppression decoding detects a B3ZS signature if a
zero is followed by a BPV that has the opposite polarity of the BPV in the previous B3ZS signature, and an HDB3
signature if two zeros are followed by a BPV that has the opposite polarity of the BPV in the previous HDB3
signature. Note: Immediately after a reset (
DRST or RST low), this bit is ignored. The first B3ZS signature is defined
as a zero followed by a BPV, and the first HDB3 signature is defined as two zeros followed by a BPV. All
subsequent B3ZS/HDB3 signatures will be determined by the setting of this bit.