DS26521L+ Maxim Integrated Products, DS26521L+ Datasheet - Page 47

• Manufacturer Part Number: DS26521L+
• Description: IC TXRX T1/E1/J1 64-LQFP
• Manufacturer: Maxim Integrated Products
• Type: Line Interface Units (LIUs)r

Specifications of DS26521L+

• Number Of Drivers/receivers: 1/1
• Protocol: T1/E1/J1
• Voltage - Supply: 3.135 V ~ 3.465 V
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Product: Framer
• Number Of Transceivers: 1
• Data Rate: 44.736 Mbps
• Supply Voltage (max): 3.465 V
• Supply Voltage (min): 3.135 V
• Supply Current (max): 220 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.9.4.3.6 Receive-Signaling Freeze
The signaling data in the four multiframe signaling buffers is frozen in a known good state upon either a loss of
synchronization (OOF event), carrier loss, or change of frame alignment. In T1 mode, this action meets the
requirements of BellCore TR-TSY-000170 for signaling freezing. To allow this freeze action to occur, the RSFE
control bit (RSIGC.1) should be set high. The user can force a freeze by setting the RSFF control bit (RSIGC.2)
high. The RSIGF output pin provides a hardware indication that a freeze is in effect. The four multiframe buffer
provides a three multiframe delay in the signaling bits provided at the RSIG pin (and at the RSER pin if receive-
signaling reinsertion is enabled). When freezing is enabled (RSFE = 1), the signaling data is held in the last known
good state until the corrupting error condition subsides. When the error condition subsides, the signaling data is
held in the old state for at least an additional 9ms (4.5ms in D4 framing mode, 6ms for E1 mode) before being
allowed to be updated with new signaling data.
The receive-signaling registers are frozen and not updated during a loss-of-sync condition. They will contain the
most recent signaling information before the LOF occurred.
8.9.4.4 Transmit SLC-96 Operation (T1 Mode Only)
In an SLC-96-based transmission scheme, the standard Fs-bit pattern is robbed to make room for a set of
message fields. The SLC-96 multiframe is made up of six D4 superframes, thus it is 72 frames long. In the 72-
frame SLC-96 multiframe, 36 of the framing bits are the normal Ft pattern and the other 36 bits are divided into
alarm, maintenance, spoiler, and concentrator bits, as well as 12 bits of the normal Fs pattern. Additional SLC-96
information can be found in BellCore document TR-TSY-000008. Registers related to the transmit FDL are shown
in
Table 8-12. Registers Related to SLC-96
Transmit FDL Register (T1TFDL)
Transmit SLC-96 Data Link Registers 1
to 3 (T1TSLC1:T1TSLC3)
Transmit Control Register 2 TCR2)
Transmit Latched Status Register 1
(TLS1)
Receive SLC-96 Data Link Registers 1
to 3 (T1RSLC1:T1RSLC3)
Receive Latched Status Register 7
(RLS7)
The
T1TFDL
The DS26521 automatically inserts the 12-bit alignment pattern in the Fs bits for the SLC-96 data link frame. Data
from
TSLC96 located at TLS1.4 is set to indicate that the SLC-96 data link buffer has been transmitted and that the user
should write new message data into T1TSLC1:T1TSLC3. The host has 9ms after the assertion of TLS1.4 to write
the registers T1TSLC1:T1TSLC3. If no new data is provided in these registers, the previous values are
retransmitted.
Table
T1TFDL
T1TSLC1:T1TSLC3
•
•
•
•
8-12.
register, the user should configure the DS26521 as shown:
TCR2.6 (TSLC96) = 1
TCR2.7 (TFDLS) = 0
TCR3.2 (TFM) = 1
TCR1.6 (TFPT) = 0
REGISTER
register is used to insert the SLC-96 message fields. To insert the SLC-96 message using the
is inserted into the remaining Fs-bit locations of the SLC-96 multiframe. The status bit
Enable transmit SLC-96.
Source FS bits via TFDL or SLC-96 formatter.
D4 framing mode.
Do not “pass through” TSER F-bits.
164h, 165h, 166h
064h, 065h, 066h
ADDRESSES
FRAMER
162h
182h
190h
096h
47 of 258
For sending messages in transmit SLC-96 Ft/Fs
bits.
Registers that control the SLC-96 overhead
values.
Transmit control for data selection source for the
Ft/Fs bits.
Status bit for indicating transmission of data link
buffer.
—
Receive SLC-96 alignment event.
DS26521 Single T1/E1/J1 Transceiver
FUNCTION