AD28msp01KST AD [Analog Devices], AD28msp01KST Datasheet - Page 13

• Manufacturer Part Number: AD28msp01KST
• Description: PSTN Signal Port
• Manufacturer: AD [Analog Devices]

REV. A
V.32 Loopback Mode
In V.32 Loopback Mode, shown in Figure 9, the AD28msp01’s
receive circuitry and transmit circuitry are locked together.
RCONV is generated internally and can be phase adjusted with
the Receive Phase Adjust Register (Control Register 4). RBIT,
RBAUD, TCONV, TBIT and TBAUD are all locked to
RCONV.
V.32ter TSYNC Mode
This mode is identical to V.32 TSYNC Mode except all clocks
are scaled by a factor of 8/7 over the corresponding V.32
TSYNC rate. In this mode, the maximum value to which the re-
ceive and transmit phase adjust registers (Control Registers 4
and 5) may be set is +192.
Both TBIT and RBIT can be set to a 19,200 Hz rate that will
not be scaled by a factor of 8/7, by setting the appropriate fields
in Control Registers 2 and 3.
ANALOG OUT
ANALOG IN
MCLK
D/A
A/D
PHASE ADJUST
PHASE ADJUST
RX CLOCKS
TX CLOCKS
TX CLOCKS
16
16
RCONV
RBAUD
TCONV
TBAUD
RBIT
TBIT
REGISTER 0
REGISTER 2
DATA
DATA
Figure 9. Loopback Mode Block Diagram
CONVERT
START
AD28msp01
RX PHASE ADJUST
REGISTER 4
CONTROL
–13–
RCONV initiates a new DAC sample update and loads Data
Register 2 with a new sample. The RCONV rate can be set to
9.6 kHz, 8.0 kHz or 7.2 kHz by setting the sample rate bit field
in Control Register 0. The bit and baud rates can be set to
any combination of clock rates listed in the control register
descriptions.
V.32ter Internal Sync Mode
This mode is identical to V.32 TSYNC Mode except all clocks
are scaled by a factor of 8/7 over the corresponding V.32
TSYNC rate. In this mode, the maximum value to which the
phase adjust registers (Control Registers 4 and 5) may be set is
+192.
Both TBIT and RBIT can be set to a 19,200 Hz rate that will
not be scaled by a factor of 8/7, by setting the appropriate fields
in Control Registers 2 and 3.
16
DSP Processor
AD28msp01