mt8889csr1 Zarlink Semiconductor, mt8889csr1 Datasheet - Page 8

• Manufacturer Part Number: mt8889csr1
• Description: Integrated Dtmf Transceiver With Adaptive Micro Interface
• Manufacturer: Zarlink Semiconductor

EXPLANATION OF EVENTS
A)
B)
C)
D)
E)
F)
EXPLANATION OF SYMBOLS
V
ESt
St/GT
RX
b3
b2
IRQ/CP
t
t
t
t
t
t
t
t
REC
REC
ID
DO
DP
DA
GTP
GTA
in
0
-RX
3
TONE BURSTS DETECTED, TONE DURATION INVALID, RX DATA REGISTER NOT UPDATED.
TONE #n DETECTED, TONE DURATION VALID, TONE DECODED AND LATCHED IN RX DATA REGISTER.
END OF TONE #n DETECTED, TONE ABSENT DURATION VALID, INFORMATION IN RX DATA REGISTER
TONE #n+1 DETECTED, TONE DURATION VALID, TONE DECODED AND LATCHED IN RX DATA REGISTER.
ACCEPTABLE DROPOUT OF TONE #n+1, TONE ABSENT DURATION INVALID, DATA REMAINS UNCHANGED.
END OF TONE #n+1 DETECTED, TONE ABSENT DURATION VALID, INFORMATION IN RX DATA REGISTER
DTMF COMPOSITE INPUT SIGNAL.
EARLY STEERING OUTPUT. INDICATES DETECTION OF VALID TONE FREQUENCIES.
STEERING INPUT/GUARD TIME OUTPUT. DRIVES EXTERNAL RC TIMING CIRCUIT.
4-BIT DECODED DATA IN RECEIVE DATA REGISTER
DELAYED STEERING. INDICATES THAT VALID FREQUENCIES HAVE BEEN PRESENT/ABSENT FOR THE
INDICATES THAT VALID DATA IS IN THE RECEIVE DATA REGISTER. THE BIT IS CLEARED AFTER THE STATUS
INTERRUPT IS ACTIVE INDICATING THAT NEW DATA IS IN THE RX DATA REGISTER. THE INTERRUPT IS
MAXIMUM DTMF SIGNAL DURATION NOT DETECTED AS VALID.
MINIMUM DTMF SIGNAL DURATION REQUIRED FOR VALID RECOGNITION.
MINIMUM TIME BETWEEN VALID SEQUENTIAL DTMF SIGNALS.
MAXIMUM ALLOWABLE DROPOUT DURING VALID DTMF SIGNAL.
TIME TO DETECT VALID FREQUENCIES PRESENT.
TIME TO DETECT VALID FREQUENCIES ABSENT.
GUARD TIME, TONE PRESENT.
GUARD TIME, TONE ABSENT.
RETAINED UNTIL NEXT VALID TONE PAIR.
RETAINED UNTIL NEXT VALID TONE PAIR.
REQUIRED GUARD TIME THUS CONSTITUTING A VALID SIGNAL. ACTIVE LOW FOR THE DURATION OF A
VALID DTMF SIGNAL.
REGISTER IS READ.
CLEARED AFTER THE STATUS REGISTER IS READ.
LEVEL
(dBm)
-25
Figure 9 - Description of Timing Events
Figure 8 - Call Progress Response
0
= Reject
= May Accept
= Accept
Zarlink Semiconductor Inc.
MT8889C
250
FREQUENCY (Hz)
8
500
750
Data Sheet