
DS26518 8-Port T1/E1/J1 Transceiver 
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NAME 
PIN 
TYPE 
FUNCTION 
MICROPROCESSOR INTERFACE 
A12 
A11 
A10 
A9 
A8 
A7 
A6 
A5 
A4 
A3 
A2 
A1 
A0 
C8 
A8 
B8 
F8 
B9 
A9 
C9 
D9 
E9 
F9 
B10 
A10 
C10 
Input 
Address [12:0]. 
This bus selects a specific register in the DS26518 during 
read/write access. A12 is the MSB and A0 is the LSB.  
D[7]/SPI_CPOL 
T9 
Input/ 
Output 
Data [7]/SPI Interface Clock Polarity 
D[7]:
 Bit 7 of the 16-bit or 8-bit data bus used to input data during register writes 
and data outputs during register reads. Not driven when 
CSB 
= 1. 
SPI_CPOL:
 This signal selects the clock polarity when SPI_SEL = 1. See Section 
9.1.2
 for detailed timing and functionality information. Default setting is low. 
Data [6]/SPI Interface Clock Phase 
D[6]:
 Bit 6 of the 16-bit or 8-bit data bus used to input data during register writes 
and data outputs during register reads. Not driven when 
CSB 
= 1. 
D[6]/SPI_CPHA 
N9 
Input/ 
Output 
SPI_CPHA:
 This signal selects the clock phase when SPI_SEL = 1. See Section 
9.1.2
 for detailed timing and functionality information. Default setting is low. 
Data [5]/SPI Bit Order Swap 
D[5]/SPI_SWAP 
M9 
Input/ 
Output 
D[5]:
 Bit 5 of the 16-bit or 8-bit data bus used to input data during register writes 
and data outputs during register reads. Not driven when 
CSB 
= 1. 
SPI_SWAP:
 This signal is active when SPI_SEL = 1. The address and data bit 
order is swapped when SPI_SWAP is high. The R/W and B bit positions are 
never changed in the control word. 
0 = LSB is transmitted and received first. 
1 = MSB is transmitted and received first. 
Data [4]. 
Bit 4 of the 8-bit data bus used to input data during register writes and 
data outputs during register reads. Not driven when 
CSB 
= 1. 
Data [3]. 
Bit 3 of the 8-bit data bus used to input data during register writes and 
data outputs during register reads. Not driven when 
CSB 
= 1. 
Data [2]/SPI Serial Interface Clock 
D[4] 
R8 
Input/ 
Output 
Input/ 
Output 
D[3] 
T8 
D[2]/SPI_SCLK 
P8 
Input/ 
Output 
D[2]:
 Bit 2 of the 8-bit data bus used to input data during register writes and data 
outputs during register reads. Not driven when 
CSB 
= 1. 
SPI_SCLK: 
SPI Serial Clock Input when SPI_SEL = 1. 
Data [1]/SPI Serial Interface Data Master Out-Slave In 
D[1]: 
Bit 1 of the 8-bit data bus used to input data during register writes, and data 
outputs during register reads. Not driven when 
CSB 
= 1. 
D[1]/SPI_MOSI 
L9 
Input/ 
Ouput 
SPI_MOSI: 
SPI Serial Data Input (Master Out-Slave In) when SPI_SEL = 1. 
Data [0]/SPI Serial Interface Data Master In-Slave Out 
D[0]/SPI_MISO 
N8 
Input/ 
Output 
D[0]:
 Bit 0 of the 8-bit data bus used to input data during register writes and data 
outputs during register reads. Not driven when 
CSB 
= 1. 
SPI_MISO: 
SPI Serial Data Output (Master In-Slave Out) when SPI_SEL = 1. 
CSB 
T7 
Input 
Chip-Select Bar. 
This active-low signal is used to qualify register read/write 
accesses. The 
RDB/DSB
 and 
WRB
 signals are qualified with 
CSB.
RDB
/ 
DSB
M8 
Input 
Read-Data Bar/Data-Strobe Bar. 
This active-low signal along with 
CSB
 qualifies 
read access to one of the DS26518 registers. The DS26518 drives the data bus 
with the contents of the addressed register while 
RDB
 and 
CSB
 are low.