mt88l89asr1 Zarlink Semiconductor, mt88l89asr1 Datasheet - Page 13

• Manufacturer Part Number: mt88l89asr1
• Description: 3 V Integrated Dtmf Transceiver With Adaptive Micro Interface
• Manufacturer: Zarlink Semiconductor

Bit
b0
b1
b2
b3
CP/DTMF
Name
TOUT
RSEL
IRQ
Tone Output Control. A logic high enables the tone output; a logic low puts the DTMF
transmitter in power-down mode. The TONE output pin is held in high impedance and the
transmit register is cleared. See Note 1 below.
Call Progress or DTMF Mode Select. A logic high enables the receive call progress mode;
a logic low enables DTMF mode. In DTMF mode the device is capable of receiving and
transmitting DTMF signals. In CP mode a rectangular wave representation of the received
tone signal will be present on the IRQ/CP output pin if IRQ has been enabled (Control
Register A, b2=1). In order to be detected, CP signals must be within the bandwidth
specified in the AC Electrical Characteristics for Call Progress.
Note: DTMF signals cannot be detected when CP mode is selected.
Interrupt Enable. A logic high enables the interrupt function; a logic low de-activates the
interrupt function. When IRQ is enabled and DTMF mode is selected (Control Register A,
b1=0), the IRQ/CP output pin will go low when either 1) a valid DTMF signal has been
received for a valid guard time duration, or 2) the transmitter is ready for more data (burst
mode only).
Register Select. A logic high selects Control Register B for the next write cycle to the
control register address. After writing to Control Register B, the following control register
write cycle will be directed to Control Register A.
RS0
0
0
1
1
Motorola
R/W
RSEL
C/R
Table 6 - Control Register A Description
0
1
0
1
b3
b3
Table 3 - Internal Register Functions
Table 4 - CRA Bit Positions
Table 5 - CRB Bit Positions
WR
0
1
0
1
Zarlink Semiconductor Inc.
Intel
S/D
IRQ
b2
b2
MT88L89
RD
1
0
1
0
13
CP/DTMF
Write to Transmit
Data Register
Read from Receive
Data Register
Write to Control Register
Read from Status Register
RxEN
Description
b1
b1
Function
ENABLE
BURST
TOUT
b0
b0
Data Sheet