MT8888C データシートの表示（PDF） - Mitel Networks
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MT8888C Datasheet PDF : 16 Pages
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MT8888C/MT8888C-1
TEST POINT
MMD6150 (or
equivalent)
5.0 VDC
2.4 kΩ
130 pF
24 kΩ
MMD7000 (or
equivalent)
TEST POINT
5.0 VDC
3 kΩ
100 pF
Test load for D0-D3 pins
Test load for IRQ/CP pin
Figure 14 - Test Circuits
INITIALIZATION PROCEDURE
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:
Control
Data
RS0 WR
RD
b3 b2 b1 b0
1) Read Status Register
1
1
0
X XXX
2) Write to Control Register
1
0
1
0 000
3) Write to Control Register
1
0
1
0 000
4) Write to Control Register
1
0
1
1 000
5) Write to Control Register
1
0
1
0 000
6) Read Status Register
1
1
0
X XXX
TYPICAL CONTROL SEQUENCE FOR BURST MODE APPLICATIONS
Transmit DTMF tones of 50 ms burst/50 ms pause and Receive DTMF Tones.
Sequence:
RS0 WR
RD
1) Write to Control Register A
1
0
1
(tone out, DTMF, IRQ, Select Control Register B)
2) Write to Control Register B
1
0
1
(burst mode)
3) Write to Transmit Data Register
0
0
1
(send a digit 7)
4) Wait for an interrupt or poll Status Register
5) Read the Status Register
1
1
0
-if bit 1 is set, the Tx is ready for the next tone, in which case...
Write to Transmit Register
0
0
1
(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
0
-if both bits are set...
Read the Receive Data Register
Write to Transmit Data Register
0
1
0
0
0
1
b3 b2 b1 b0
1 101
0 000
0 111
X XXX
0 101
X XXX
X XXX
0 101
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 15 - Application Notes
4-101
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