73K324L
CCITT V.22bis,V.23,V.22,V.21, Bell 212A
Single-Chip Modem
DATA SHEET
PIN DESCRIPTION
POWER
NAME
GND
VDD
VREF
ISET
TYPE
I
I
O
I
DESCRIPTION
System Ground.
Power supply input, 5V -5% +10%. Bypass with 0.22 µF and 22 µF capacitors to
GND.
An internally generated reference voltage. Bypass with 0.22 µF capacitor to GND.
Chip current reference. Sets bias current for op-amps. The chip current is set by
connecting this pin to VDD through a 2 MΩ resistor. Iset should be bypassed to
GND with a 0.22 µF capacitor.
PARALLEL MICROPROCESSOR INTERFACE
ALE
AD0- AD7
CS
I
I/O /
Tristate
I
Address latch enable. The falling edge of ALE latches the address on AD0-AD2
and the chip select on
CS.
Address/data bus. These bidirectional tri-state multi-plexed lines carry information
to and from the internal registers.
Chip select. A low on this pin allows a read cycle or a write cycle to occur. AD0-
AD7 will not be driven and no registers will be written if
CS
(latched) is not active.
CS
is latched on the falling edge of ALE.
Output clock. This pin is selectable under processor control to be either the crystal
frequency (for use as a processor clock) or 16 x the data rate for use as a baud
rate clock in QAM/DPSK modes only. The pin defaults to the crystal frequency on
reset.
Interrupt. This open drain weak pull-up, output signal is used to inform the
processor that a detect flag has occurred. The processor must then read the detect
register to determine which detect triggered the interrupt.
INT
will stay active until
the processor reads the detect register or does a full reset.
Read. A low requests a read of the 73K324L internal registers. Data cannot be
output unless both
RD
and the latched
CS
are active or low.
Reset. An active high signal on this pin will put the chip into an inactive state. All
control register bits (CR0, CR1, CR2, CR3, Tone) will be reset. The output of the
CLK pin will be set to the crystal frequency. An internal pull down resistor permits
power on reset using a capacitor to VDD.
Write. A low on this informs the 73K324L that data is available on AD0-AD7 for
writing into an internal register. Data is latched on the rising edge of
WR.
No data
is written unless both
WR
and the latched
CS
are low.
CLK
O
INT
O
RD
RESET
I
I
WR
I
NOTE: The Serial Control mode is provided by tying ALE high and
CS
low. In this configuration AD7 becomes
DATA and AD0, AD1 and AD2 become the address only. See the serial time diagrams on page 23.
Page: 4 of 30
©
2005, 2008 TERIDIAN Semiconductor Corporation
Rev 7.1
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
