
DS26518 8-Port T1/E1/J1 Transceiver 
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NAME 
PIN 
TYPE 
FUNCTION 
TRANSMIT FRAMER 
TSER1 
TSER2 
TSER3 
TSER4 
TSER5 
TSER6 
TSER7 
TSER8 
TCLK1 
TCLK2 
TCLK3 
TCLK4 
TCLK5 
TCLK6 
TCLK7 
TCLK8 
F6 
E7 
R4 
N7 
M10 
L11 
F10 
D12 
C5 
D7 
P5 
L8 
L10 
N11 
E10 
B13 
Input 
Transmit NRZ Serial Data 1 to 8. 
These pins are sampled on the falling edge of 
TCLKn when the transmit-side elastic store is disabled. These pins are sampled 
on the falling edge of TSYSCLKn when the transmit-side elastic store is enabled. 
In IBO mode, data for multiple framers can be used in high-speed multiplexed 
scheme. This is described in Section 
9.8.2
. The table there presents the 
combination of framer data for each of the streams. 
TSYSCLKn is used as a reference when IBO is invoked. See 
Table 9-8
. 
Input 
Transmit Clock 1 to 8. 
A 1.544MHz or a 2.048MHz primary clock. Used to clock 
data through the transmit side of the transceiver. TSERn data is sampled on the 
falling edge of TCLKn. TCLKn is used to sample TSERn when the elastic store is 
not enabled or IBO is not used. 
TSYSCLK1 
P13 
Input 
Transmit System Clock 1. 
1.544MHz, 2.048MHz, 4.096MHz, 8.192MHz, or 
16.384MHz clock. Only used when the transmit-side elastic store function is 
enabled. Should be tied low in applications that do not use the transmit-side 
elastic store. The clock can be 4.096MHz, 8.912MHz, or 16.384MHz when IBO 
mode is used. TSYSCLK1 does not have an internal pulldown resistor. 
Note:
 If 
the 
GTCR1
.528MD bit is set, TSYSCLK1 becomes the master TSYSCLK for all 
framers.
TSYSCLK2/ 
AL/RSIGF/FLOS2 
TSYSCLK3/ 
AL/RSIGF/FLOS3 
TSYSCLK4/ 
AL/RSIGF/FLOS4 
TSYSCLK5/ 
AL/RSIGF/FLOS5 
TSYSCLK6/ 
AL/RSIGF/FLOS6 
TSYSCLK7/ 
AL/RSIGF/FLOS7 
TSYSCLK8/ 
AL/RSIGF/FLOS8 
TSYNC1/ 
TSSYNCIO1 
TSYNC2/ 
TSSYNCIO2 
TSYNC3/ 
TSSYNCIO3 
TSYNC4/ 
TSSYNCIO4 
TSYNC5/ 
TSSYNCIO5 
TSYNC6/ 
TSSYNCIO6 
TSYNC7/ 
TSSYNCIO7 
F3 
L3 
P3 
P14 
L14 
F14 
C14 
Input with 
internal 
pulldown/ 
Output 
Transmit System Clock 2 to 8. 
1.544MHz, 2.048MHz, 4.096MHz, 8.192MHz, or 
16.384MHz clock. Only used when the transmit-side elastic store function is 
enabled. Should be tied low in applications that do not use the transmit-side 
elastic store. The clock can be 4.096MHz, 8.912MHz, or 16.384MHz when IBO 
mode is used. TSYSCLK1 does not have an internal pulldown resistor. 
Note:
 If 
the 
GTCR1
.528MD bit is set, TSYSCLK1 becomes the master TSYSCLK for all 
framers. 
Analog Loss/Receive-Signaling Freeze/Framer LOS. 
Analog LOS reflects the 
LOS (loss of signal) detected by the LIU front-end and framer LOS is LOS 
detection by the corresponding framer; the same pins can reflect receive-
signaling freeze indications. This selection can be made by settings in the Global 
Transceiver Clock Control Register 1 (
GTCCR1
). 
AL/RSIGF/FLOS[8:2] is available only by setting the 
GTCR1
.528MD bit to 1.
B4 
F7 
M6 
M7 
N10 
T12 
B11 
TSYNC8/ 
TSSYNCIO8 
A13 
Input/ 
Output 
Transmit Synchronization 1 to 8. 
A pulse at these pins establishes either frame 
or multiframe boundaries for the transmit side. These signals can also be 
programmed to output either a frame or multiframe pulse. If these pins are set to 
output pulses at frame boundaries, they can also be set to output double-wide 
pulses at signaling frames in T1 mode. The operation of these signals is 
synchronous with TCLK[8:1]. 
Transmit System Synchronization In. 
These pins are selected when the 
transmit-side elastic store is enabled. A pulse at these pins establishes either 
frame or multiframe boundaries for the transmit side. Should be tied low in 
applications that do not use the transmit-side elastic store. The operation of this 
signal is synchronous with TSYSCLK[8:1]. 
Transmit System Synchronization Out. 
If configured as an output and the 
transmit elastic store is enabled, an 8kHz pulse synchronous to the BPCLK1 will 
be generated. This pulse in combination with BPCLK1 can be used as an IBO 
master. TSSYNCIOn can be used as a source to RSYNCn and TSSYNCIOn of 
another DS26518 or RSYNC and TSSYNC of other Dallas Semiconductor parts. 
Note:
 TSSYNCIO[8:1] are not used when 
GTCR1
.528MD is set. When 
GTCR1
.528MD is set, the TSSYNCIO pin (N13) is used.