MT8889CN Zarlink Semiconductor, Inc., MT8889CN Datasheet - Page 17

• 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 after power
up. The initialization procedure should be implemented 100ms after power up.
Description:
1) Read Status Register
2) Write to Control Register
3) Write to Control Register
4) Write to Control Register
5) Write to Control Register
6) Read Status Register
Transmit DTMF tones of 50 ms burst/50 ms pause and Receive DTMF Tones.
Sequence:
1) Write to Control Register A
2) Write to Control Register B
3) Write to Transmit Data Register
4) Wait for an Interrupt or Poll Status Register
5) Read the Status Register
NOTE: IN THE TX BURST MODE, STATUS REGISTER BIT 1 WILL NOT BE SET UNTIL 100 ms ( 2 ms) AFTER THE DATA IS
WRITTEN TO THE TX DATA REGISTER. IN EXTENDED BURST MODE THIS TIME WILL BE DOUBLED TO 200 ms ( 4 ms)
Read the Receive Data Register
(tone out, DTMF, IRQ, Select Control Register B)
(burst mode)
(send a digit 7)
-if bit 1 is set, the Tx is ready for the next tone, in which case ...
Write to Transmit Register
(send a digit 5)
-if bit 2 is set, a DTMF tone has been received, in which case....
-if both bits are set...
Read the Receive Data Register
Write to Transmit Data Register
TYPICAL CONTROL SEQUENCE FOR BURST MODE APPLICATIONS
INITIALIZATION PROCEDURE
RS0
Figure 17 - Application Notes
1
1
1
1
1
1
Motorola
RS0
1
1
0
1
0
0
0
0
Zarlink Semiconductor Inc.
MT8889C
R/W
1
0
0
0
0
1
R/W
0
0
0
1
0
1
1
0
17
WR
WR
0
0
0
1
0
1
1
0
1
0
0
0
0
1
Intel
RD
RD
0
1
1
1
1
0
1
1
1
0
1
0
0
1
1
0
0
X
0
X
X
0
b3
b3
X
0
0
1
0
X
b2
1
0
1
X
1
X
X
1
b2
X
0
0
0
0
X
Data
b1
b1
0
0
1
X
0
X
X
0
X
0
0
0
0
X
Data Sheet
b0
1
0
1
X
1
X
X
1
b0
X
X
0
0
0
0