MT8880CE1 Zarlink, MT8880CE1 Datasheet - Page 14

• Manufacturer Part Number: MT8880CE1
• Description: DTMF TXRX 3.58MHz CMOS 5V 20-Pin PDIP Tube
• Manufacturer: Zarlink

Specifications of MT8880CE1

• Package: 20PDIP
• Operating Frequency: 3.58 MHz
• Typical Supply Current: 11 mA
• Typical Operating Supply Voltage: 5 V
• Minimum Operating Supply Voltage: 4.75 V
• Maximum Operating Supply Voltage: 5.25 V

BIT
BIT
b0
b1
b2
b3
b0
b1
b2
b3
TRANSMIT DATA
REGISTER EMPTY
(BURST MODE ONLY)
RECEIVE DATA REGISTER
FULL
DELAYED STEERING
BURST
NAME
TEST
C/R
S/D
NAME
IRQ
COLUMN/ROW TONES
SINGLE /DUAL TONE
BURST MODE
GENERATION
TEST MODE
FUNCTION
Table 6 - Control Register B Description
Table 7 - Status Register Description
Interrupt has occurred. Bit one (b1) or
bit two (b2) is set.
Pause duration has terminated and
transmitter is ready for new data.
Valid data is in the Receive Data
Register.
Set upon the valid detection of the
absence of a DTMF signal.
Zarlink Semiconductor Inc.
STATUS FLAG SET
MT8880C
DESCRIPTION
A logic ‘0’ enables the burst mode. When this mode is selected,
data corresponding to the desired DTMF tone pair can be written to
the Transmit Register resulting in a tone burst of a specific duration
(see AC Characteristics). Subsequently, a pause of the same
duration is induced. Immediately following the pause, the Status
Register is updated indicating that the Transmit Register is ready
for further instructions and an interrupt will be generated if the
interrupt mode has been enabled. Additionally, if call progress
(CP) mode has been enabled, the burst and pause duration is
increased by a factor of two. When the burst mode is not selected
(logic ‘1’) tone bursts of any desired duration may be generated.
By enabling the test mode (logic’1’), the IRQ/CP pin will present
the delayed steering (inverted) signal from the DTMF receiver.
Refer to Figure 9 (b3 waveform) for details concerning the output
waveform. DTMF mode must be selected (CRA b1=0) before test
mode can be implemented.
A logic ‘0’ will allow Dual Tone Multi-Frequency signals to be
produced. If single tone generation is enabled (logic ‘1’), either
row or column tones (low group or high group) can be generated
depending on the state of b3 in Control Register B.
When used in conjunction with b2 (above) the transmitter can be
made to generate single row or single column frequencies. A logic
‘0’ will select row frequencies and a logic ‘1’ will select column
frequencies.
14
Interrupt is inactive. Cleared after
Status Register is read.
Cleared after Status Register is read or
when in non-burst mode.
Cleared after Status Register is read.
Cleared upon the detection of a valid
DTMF signal.
STATUS FLAG CLEARED
Data Sheet