73K224BL
V.22bis, V.22, V.21, Bell 212A, 103
Single-Chip Modem w/ Integrated Hybrid
DATA SHEET
SERIAL CONTROL INTERFACE MODE
The serial Command mode allows access to the
73K224BL control and status registers via a serial
control port. In this mode the AD0, AD1, and AD2 lines
provide register addresses for data passed through the
AD7 (DATA) pin under control of the RD and WR lines.
A read operation is initiated when the RD line is taken
low. The next eight cycles of EXCLK will then transfer
out eight bits of the selected address location LSB
first. A write takes place by shifting in eight bits of data
LSB first for eight consecutive cycles of EXCLK. WR is
then pulsed low and data transfer into the selected
register occurs on the rising edge of WR.
DTMF GENERATOR
The DTMF generator controls the sending of the
sixteen standard DTMF tone pairs. The tone pair sent
is determined by selecting transmit DTMF (bit D4) and
the 4 DTMF bits (D0-D3) of the Tone Register.
Transmission of DTMF tones from TXA is gated by the
transmit enable bit of CR0 (bit D1) as with all other
analog signals.
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© 2005, 2008 TERIDIAN Semiconductor Corporation
Rev 7.1