MT8889CN Zarlink Semiconductor, Inc., MT8889CN Datasheet - Page 13

• Manufacturer Part Number: MT8889CN
• Description: Integrated DTMF Transceiver with Adaptive Micro Interface
• Manufacturer: Zarlink Semiconductor, Inc.

A software reset must be included at the beginning of all programs to initialize the control registers upon power-up
or power reset (see Figure 17). Refer to Tables 4-7 for bit descriptions of the two control registers.
The multiplexed IRQ/CP pin can be programmed to generate an interrupt upon validation of DTMF signals or when
the transmitter is ready for more data (burst mode only). Alternatively, this pin can be configured to provide a
square-wave output of the call progress signal. The IRQ/CP pin is an open drain output and requires an external
pull-up resistor (see Figure 15).
RS0
0
0
1
1
RSEL
C/R
b3
b3
Table 3 - Internal Register Functions
Motorola
R/W
0
1
0
1
Table 4 - CRA Bit Positions
Table 5 - CRB Bit Positions
Zarlink Semiconductor Inc.
S/D
IRQ
b2
b2
WR
MT8889C
0
1
0
1
Intel
RD
13
1
0
1
0
CP/DTMF
TEST
Write to Transmit
Data Register
Read from Receive
Data Register
Write to Control Register
Read from Status Register
b1
b1
FUNCTION
ENABLE
BURST
TOUT
b0
b0
Data Sheet