MT8888CE1 Zarlink, MT8888CE1 Datasheet - Page 13

• Manufacturer Part Number: MT8888CE1
• Description: DTMF TXRX 3.58MHz CMOS 5V 20-Pin PDIP Tube
• Manufacturer: Zarlink

Specifications of MT8888CE1

• Package: 20PDIP
• Operating Frequency: 3.58 MHz
• Typical Supply Current: 7 mA
• Typical Operating Supply Voltage: 5 V
• Minimum Operating Supply Voltage: 4.75 V
• Maximum Operating Supply Voltage: 5.25 V

BIT
b0
b1
b2
b3
CP/DTMF
NAME
TOUT
RSEL
IRQ
Tone Output Control. A logic high enables the tone output; a logic low turns the tone output
off. This bit controls all transmit tone functions.
Call Progress or DTMF Mode Select. A logic high enables the receive call progress mode;
a logic low enables DTMF mode. In DTMF mode the device is capable of receiving and
transmitting DTMF signals. In CP mode a rectangular wave representation of the received
tone signal will be present on the IRQ/CP output pin if IRQ has been enabled (control
register A, b2=1). In order to be detected, CP signals must be within the bandwidth
specified in the AC Electrical Characteristics for Call Progress.
Note: DTMF signals cannot be detected when CP mode is selected.
Interrupt Enable. A logic high enables the interrupt function; a logic low deactivates the
interrupt function. When IRQ is enabled and DTMF mode is selected (control register A,
b1=0), the IRQ/CP output pin will go low when either 1) a valid DTMF signal has been
received for a valid guard time duration, or 2) the transmitter is ready for more data (burst
mode only).
Register Select. A logic high selects control register B for the next write cycle to the control
register address. After writing to control register B, the following control register write cycle
will be directed to control register A.
RS0
0
0
1
1
RSEL
Table 6 - Control Register A Description
WR
C/R
b3
b3
0
1
0
1
Table 3 - Internal Register Functions
Table 4 - CRA Bit Positions
Table 5 - CRB Bit Positions
RD
1
0
1
0
Zarlink Semiconductor Inc.
S/D
IRQ
Write to Transmit Data Register
Read from Receive Data Register
Write to Control Register
Read from Status Register
b2
b2
MT8888C
13
CP/DTMF
DESCRIPTION
TEST
FUNCTION
b1
b1
ENABLE
BURST
TOUT
b0
b0
Data Sheet