mt8885an1 Zarlink Semiconductor, mt8885an1 Datasheet - Page 8

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

2.0
A call progress mode, using the MT8885, can be selected to allow the detection of various tones, which identify the
progress of a telephone call on the network. The call progress tone input and DTMF input are common, however,
call progress tones can only be detected when CP mode has been selected.
V
ESt
St/GT
RX
b3
b2
Read
Status
Register
IRQ/CP
in
EVENTS
0
-RX
Call Progress Filter
3
t
REC
DECODED TONE # (n-1)
A
LEVEL
(dBm)
-25
t
DP
= Reject
= May Accept
= Accept
Figure 7 - Receiver Timing Diagram
Figure 8 - Call Progress Response
0
t
Zarlink Semiconductor Inc.
REC
TONE #n
B
MT8885
250
t
GTP
FREQUENCY (Hz)
8
t
PStRX
t
PStb3
t
# n
ID
500
C
t
DA
t
GTA
TONE
#n + 1
D
750
t
DO
E
TONE
#n + 1
# (n + 1)
Data Sheet
F
V
TSt