DS110RT410 Datasheet, PDF (19/40 Pages) Texas Instruments – DS110RT410 Low Power Multi-Rate Quad Channel Retimer

DS110RT410
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REGISTER INFORMATION
SNLS460 – MAY 2013
There are two types of device registers in the DS110RT410. These are the control/shared registers and the
channel registers. The control/shared registers control or allow observation of settings which affect the operation
of all channels of the DS110RT410. They are also used to select which channel of the device is to be the target
channel for reads from and writes to the channel registers.
The channel registers are used to set all the configuration settings of the DS110RT410. They provide
independent control for each channel of the DS110RT410 for all the settable device characteristics.
Any registers not described in the tables that follow should be treated as reserved. The user should not try to
write new values to these registers. The user-accessible registers described in the tables that follow provide a
complete capability for customizing the operation of the DS110RT410 on a channel-by-channel basis.
Bit Fields in the Register Set
Many of the registers in the DS110RT410 are divided into bit fields. This allows a single register to serve multiple
purposes, which may be unrelated.
Often configuring the DS110RT410 requires writing a bit field that makes up only part of a register value while
leaving the remainder of the register value unchanged. The procedure for accomplishing this is to read in the
current value of the register to be written, modify only the desired bits in this value, and write the modified value
back to the register. Of course, if the entire register is to be changed, rather than just a bit field within the
register, it is not necessary to read in the current value of the register first.
In all the register configuration procedures described in the following sections, this procedure should be kept in
mind. In some cases, the entire register is to be modified. When only a part of the register is to be changed,
however, the procedure described above should be used.
Writing to and Reading from the Control/Shared Registers
Any write operation targeting register 0xff writes to the control/shared register 0xff. This is the only register in the
DS110RT410 with an address of 0xff.
Bit 2 of register 0xff is used to select either the control/shared register set or a channel register set. If bit 2 of
register 0xff is cleared (written with a 0), then all subsequent read and write operations over the SMBus are
directed to the control/shared register set. This situation persists until bit 2 of register 0xff is set (written with a 1).
There is a register with address 0x00 in the control/shared register set, and there is also a register with address
0x00 in each channel register set. If you read the value in register 0x00 when bit 2 of register 0xff is cleared to 0,
then the value returned by the DS110RT410 is the value in register 0x00 of the control/shared register set. If you
read the value in register 0x00 when bit 2 of register 0xff is set to 1, then the value returned by the DS110RT410
is the value in register 0x00 of the selected channel register set. The channel register set is selected by bits 1:0
of register 0xff.
If bit 3 of register 0xff is set to 1 and bit 2 of register 0xff is also set to 1, then any write operation to any register
address will write all the channel register sets in the DS110RT410 simultaneously. This situation will persist until
either bit 3 of register 0xff or bit 2 of register 0xff is cleared. Note that when you write to register 0xff,
independent of the current settings in register 0xff, the write operation ALWAYS targets the control/shared
register 0xff. This channel select register, register 0xff, is unique in this regard.
Table 5 shows the control/shared register set. Any register addresses or register bits in the control/shared
register set not shown in this table should be considered reserved. In this table, the mode is either R for Read-
Only, R/W for Read-Write, or R/W/SC for Read-Write-Self-Clearing. If you try to write to a Read-Only register, the
DS110RT410 will ignore it.
Address (Hex)
Bits
0x00
7:4
0x01
7:5
4:0
Table 5. Control/Shared Registers
Default Value (Hex)
0x0
0x6
0x10
Mode
R
R
R
Description
SMBus Address Strap Observation <3:0>
Device Revision
Device ID
Copyright © 2013, Texas Instruments Incorporated
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