Specifications
Chapter 3 – SocketModem (MT5634SMI-34 & MT5634SMI-92)
Multi-Tech Systems, Inc. Universal Socket Hardware Guide for Developers (S000342C) 67
Parallel Configuration
The parallel configuration is not compatible with the serial universal socket.
The MT5634SMI-P (Parallel) SocketModem uses a 22-pin interface to provide an on-board DAA with tip and ring
connections, audio circuit for call-progress monitoring, and parallel interface.
Note: The bolded, shaded pins are the active MT5634SMI-P (Parallel) pins.
Parallel SocketModem Pins
Pin Descriptions for a Parallel SocketModem Device
Pin # Signal I/O Description
1 Tip I/O
Telephone Line Interface – TIP
2 Ring I/O
Telephone Line Interface – RING
24
–
RESET I
Modem Reset (with pull-up). Active low –RESET input resets the SocketModem logic and
returns AT command set to original factory defaults or to NVRAM 'stored values' . The modem
is ready to accept commands within 6.5 seconds of power-on or reset. Reset must be asserted
for a minimum of 30ms.
25 A1 I
Host Bus Address Line 1
26 DGND GND
Digital Ground
27 D7 O
Host Bus Data Line 7
29 D2 O
Host Bus Data Line 2
30 INT O
Host Bus Interrupt Line. INT output is set high when the receiver error flag, receiver data
available, transmitter holding register empty, or modem status interrupt have an active high
condition. INT is reset low upon the appropriate interrupt service or master reset operation.
31 A0 I
Host Bus Address Line 0.
32 –WR I
Host Bus Write. –WR is an active low, write control input. When –DS is low, –WR low allows
the host to write data or control words into a selected modem register.
33 –RD I
Host Bus Read. –RD is an active low, read control input. When –DS is low, –RD low allows
the host to read status information or data from a selected modem register.
34 A2 I
Host Bus Address Line 2
35 D4 O
Host Bus Data Line 4
36 D5 O
Host Bus Data Line 5
37 D0 O
Host Bus Data Line 0
38 D1 O
Host Bus Data Line 1
39 D3 O
Host Bus Data Line 3
40 –DS I
Host Bus Device Select. –DS input low enables the modem for read or write.
41 D6 O
Host Bus Data Line 6
61 VCC PWR
+5 V or 3.3 V Supply (depends upon model).
63 AGND GND
Analog Ground. This is tied common with DGND on the SocketModem. To minimize potential
ground noise issues, connect audio circuit return to AGND.
64 SPKR O
Speaker Output. SPKR is a single ended-output. It is tied to the CODEC through a series 6.8K
resistor and .1uf cap.