Advance Information
MT88L85
INITIALIZATION PROCEDURE
A software reset must be included at the beginning of all programs to initialize the control registers after
power up.
Description:
1)
2)
3)
4)
5)
6)
Read Status Register
Write to Control Register
Write to Control Register
Write to Control Register
Write to Control Register
Read Status Register
Intel
Motorola
WR RD
RS0
R/W
1
1
1
0
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
1
1
0
Data
b2
X
0
0
0
0
X
b3
X
0
0
1
0
X
b1
X
0
0
0
0
X
b0
X
0
0
0
0
X
TYPICAL CONTROL SEQUENCE FOR BURST MODE APPLICATIONS
Transmit DTMF tones of 50 ms burst/50 ms pause and Receive DTMF Tones.
Sequence:
1)
2)
3)
4)
5)
RS0
Write to Control Register A
1
(tone out, DTMF, IRQ, Select Control Register B)
Write to Control Register B
1
(burst mode)
Write to Transmit Data Register
0
(send a digit 7)
Wait for an Interrupt or Poll Status Register
Read the Status Register
1
R/W
0
0
0
WR RD
0
1
0
0
1
1
b3
1
0
0
b2
1
0
1
b1
0
0
1
b0
1
0
1
1
1
0
X
X
X
X
-if bit 1 is set, the Tx is ready for the next tone, in which case ...
Write to Transmit Register
0
0
0
(send a digit 5)
-if bit 2 is set, a DTMF tone has been received, in which case ....
Read the Receive Data Register
0
1
1
-if both bits are set ...
Read the Receive Data Register
Write to Transmit Data Register
1
0
1
0
1
0
X
X
X
X
0
0
1
0
1
0
0
1
X
0
X
1
X
0
X
1
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)
Figure 14 - Application Notes
4-83
MITEL [ MITEL NETWORKS CORPORATION ]
