mt8885an1 Zarlink Semiconductor, mt8885an1 Datasheet - Page 17

• Manufacturer Part Number: mt8885an1
• Description: Integrated Dtmf Transceiver With Power-down And Adaptive Micro Interface
• Manufacturer: Zarlink Semiconductor

A software reset must be included at the beginning of all programs to initialize the control registers 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 (
WRITTEN TO THE TX DATA REGISTER. IN EXTENDED BURST MODE THIS TIME WILL BE DOUBLED TO 200 ms (
(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....
Read the Receive Data Register
-if both bits are set...
Read the Receive Data Register
Write to Transmit Data Register
TYPICAL CONTROL SEQUENCE FOR BURST MODE APPLICATIONS
INITIALIZATION PROCEDURE
Figure 14 - Application Notes
Zarlink Semiconductor Inc.
MT8885
RS0
RS0
1
1
1
1
1
1
0
1
0
0
0
0
1
1
17
Motorola
R/W
R/W
1
0
0
0
0
1
0
0
0
1
0
1
1
0
WR RD
WR RD
1
0
0
0
0
1
0
0
0
1
0
1
1
0
Intel
0
1
1
1
1
0
1
1
1
0
1
0
0
1
±
2 ms) AFTER THE DATA IS
b3
b3
X
0
0
1
0
X
1
0
0
X
0
X
X
0
Data
b2
b2
X
0
0
0
0
X
1
0
1
X
1
X
X
1
±
b1
b1
X
0
0
0
0
X
0
0
1
X
0
X
X
0
Data Sheet
4 ms)
b0
b0
X
0
0
0
0
X
1
0
1
X
1
X
X
1