MT8880CN Zarlink Semiconductor, Inc., MT8880CN Datasheet - Page 12

• Manufacturer Part Number: MT8880CN
• Description: DTMF Transceiver, 3.58MHz, 5V, CMOS, 24-SSOP
• Manufacturer: Zarlink Semiconductor, Inc.

MT8880C
12
EXAMPLE 1: 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
EXAMPLE 2: Transmit DTMF tones of 50 ms burst/50 ms pause and Receive DTMF Tones
Description
1) Write to Control Register A
2) Write to Control Register B
3) Write to Transmit Data Register
--------------------------------------wait for an interrupt or poll Status Register ----------------------------------------------
4) 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 (
-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
(tone out, DTMF, IRQ, Select Control Register B)
(burst mode)
(send a digit 7)
ISO
6802
Address
2
VMA
-CMOS
Data
R/W
IRQ
E
Peripheral decode
Figure 15 - MT8880C to 6802 Interface
Figure 16 - Application Hints
CS
CS
+5V
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Control
RS0
RS0
3.3k
1
1
1
1
1
1
1
1
0
1
0
0
0
0
R/W
R/W
1
0
0
0
0
1
0
0
0
1
0
1
1
0
IRQ
RS0
CS
R/W
Φ2
Data
b3
b3
MT8880C
X
0
0
1
0
X
1
0
0
X
0
X
X
0
±
2 ms) AFTER THE DATA IS
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
±
4 ms)
.
b0
b0
X
0
0
0
0
X
1
0
1
X
1
X
X
1