SI2493-C-FS Silicon Laboratories Inc, SI2493-C-FS Datasheet - Page 69

• Manufacturer Part Number: SI2493-C-FS
• Description: IC ISOMODEM SYSTEM-SIDE 16SOIC
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2493-C-FS

• Mfg Application Notes: SI2493/57/34/15/04, Appl Note AN93
• Data Format: V.21, V.22, V.23, V.29, V.32, V.34, V.90, V.92, Bell 103, Bell 212A
• Baud Rates: 56k
• Interface: UART
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.3.11. U-Registers
U-Registers (user-access registers) are 16-bit registers
directly written by the AT:Uhh command and read by the
AT:R (read all U-Registers) or AT:Rhh (read U-Register
hh) commands. See the AT command list in Table 18.
The U-Register number is the last two digits of the
register’s hexadecimal address. All values associated
with the U-Registers, the address, and the value written
to or read from the register are hexadecimal.
Some U-Registers are reserved and not available to the
user. Therefore, there are gaps in the available U-
Register address sequence. Additionally, some bits
within available U-Registers are reserved. Any attempt
to write to a non-listed U-Register or to write a reserved
bit to a value other than 0
modem operation.
There are two types of U-Registers. The first represents
a single 16-bit term, such as a filter coefficient,
threshold, delay, or other quantity. These registers can
be read from or written to as a single 16-bit value. The
second type of U-Register is bit-mapped. Bit-mapped
registers are written and/or read in hexadecimal, but
each bit or combination of bits in the register represents
an independent value or status information.
Register Address
U0A
U0B
U0C
U0D
U0E
U00
U01
U02
U03
U04
U05
U06
U07
U08
U09
0x000C
0x000D
0x000A
0x000B
0x000E
0x0000
0x0001
0x0002
0x0003
0x0004
0x0005
0x0006
0x0007
0x0008
0x0009
(Hex)
DT1A0
DT1B1
DT1B2
DT1A2
DT1A1
DT2A0
DT2B1
DT2B2
DT2A2
DT2A1
DT3A0
DT3B1
DT3B2
DT3A2
DT3A1
Name
b
causes unpredictable
Dial tone detect filters stage 1 biquad coefficients.
Dial tone detect filters stage 2 biquad coefficients.
Dial tone detect filters stage 3 biquad coefficients.
Table 32. U-Register Descriptions
Rev. 0.9
These individual bits are used to enable or disable
features and indicate states. Groups of bits in a bit-
mapped register can be used to represent a value. Bits
in these registers can be read/write, read only, reserved,
or they may be required to be set as a 1 or 0. Most
reserved bits return a 0 when read. Pay particular
attention when writing to bit-mapped registers to ensure
no reserved bits are overwritten. When changing bits in
a U-register with reserved bits, use a Read, Modify,
Write procedure. Read the register value with AT:R;
modify the desired bits, then write the new value with
AT:U. This will ensure the reserved bits are not altered.
All U-Registers revert to their default setting after a
reset.
The U-Registers can be broken into three groups: Call
Progress (U0–U33, U49–U4C), Dialing (U37–U48), and
Line Interface and Extended Functions (U4D–UA9).
Table 32 lists the available U-Registers, a brief
description,
summarizes the signals and values available in the bit-
mapped registers.
Description
and
their
default
values.
AN93
Default
0x00A0
0x6EF1
0xC4F4
0xC000
0x78B0
0xC305
0xB50A
0x0800
0x0000
0x0000
0x0000
0x0000
0x0000
0x00A0
0x4000
Table 33
Value
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