參數(shù)資料
型號(hào): PCA3354CH
廠商: NXP SEMICONDUCTORS
元件分類: 微控制器/微處理器
英文描述: 8-bit microcontrollers with DTMF generator and 256 bytes EEPROM
中文描述: 8-BIT, MROM, 16 MHz, MICROCONTROLLER, PQFP44
封裝: 14 X 14 X 2.20 MM, PLASTIC, QFP-44
文件頁(yè)數(shù): 9/32頁(yè)
文件大小: 221K
代理商: PCA3354CH
1996 Dec 18
9
Philips Semiconductors
Product specification
8-bit microcontrollers with DTMF
generator and 256 bytes EEPROM
PCA3354C; PCD3354A
If EDCO = 1 and DIV3 = 1 in the MDYCON register:
a square wave with the frequency f
DTMF
=
1
3
×
f
xtal
is
output on the derivative port line DP1.7/DCO. If EDCO = 1
and DIV3 = 0: a square wave with the frequency
f
DTMF
= f
xtal
is output on the derivative port line
DP1.7/DCO.
The melody output drive depends on the configuration of
port P1.7/MDY, see Chapter 13, Table 24.
6.4
Frequency registers
The two frequency registers HGF and LGF define two
frequencies. From these, the digital sine synthesizers
together with the Digital-to-Analog Converters (DACs)
construct two sine waves. Their amplitudes are precisely
scaled according to the bandgap voltage reference. This
ensures tone output levels independent of supply voltage
and temperature. The amplitude of the Low Group
Frequency sine wave is attenuated by 2 dB compared to
the amplitude of the High Group Frequency sine wave.
The two sine waves are summed and then filtered by an
on-chip switched capacitor and RC low-pass filters.
These guarantee that all DTMF tones generated fulfil the
CEPT recommendations with respect to amplitude,
frequency deviation, total harmonic distortion and
suppression of unwanted frequency components.
The value 00H in a frequency register stops the
corresponding digital sine synthesizer. If both frequency
registers contain 00H, the whole frequency generator is
shut off, resulting in lower power consumption.
The frequency ‘f’ of the sine wave generated from either of
the frequency registers is a function of the clock frequency
‘f
xtal
’ and the decimal value ‘x’ held in the register.
The equation relating these variables is:
; where 60
x
255.
The frequency limitation given by x
60 is due to the
low-pass filters which would attenuate higher frequency
sine waves.
6.5
DTMF frequencies
Assuming an oscillator frequency f
xtal
= 3.58 MHz, the
DTMF standard frequencies can be implemented as
shown in Table 6.
The relationship between telephone keyboard symbols,
DTMF frequency pairs and the corresponding frequency
register contents are given in Table 7.
f
f
23 x
2
+
)
[
]
--------------------------------
=
Table 6
DTMF standard frequencies and their
implementation; value = LGF, HGF contents
Table 7
Dialling symbols, corresponding DTMF
frequency pairs and frequency register contents
VALUE
(HEX)
FREQUENCY (Hz)
DEVIATION
STANDARD
GENERATED
(%)
(Hz)
DD
C8
B5
A3
7F
72
67
5D
697
770
852
941
1209
1336
1477
1633
697.90
770.46
850.45
943.23
1206.45
1341.66
1482.21
1638.24
0.13
0.06
0.18
0.24
0.21
0.42
0.35
0.32
0.90
0.46
1.55
2.23
2.55
5.66
5.21
5.24
TELEPHONE
KEYBOARD
SYMBOLS
DTMF FREQ.
PAIRS
(Hz)
LGF
VALUE
(HEX)
HGF
VALUE
(HEX)
0
1
2
3
4
5
6
7
8
9
A
B
C
D
#
(941, 1336)
(697, 1209)
(697, 1336)
(697, 1477)
(770, 1209)
(770, 1336)
(770, 1477)
(852, 1209)
(852, 1336)
(852, 1477)
(697, 1633)
(770, 1633)
(852, 1633)
(941, 1633)
(941, 1209)
(941, 1477)
A3
DD
DD
DD
C8
C8
C8
B5
B5
B5
DD
C8
B5
A3
A3
A3
72
7F
72
67
7F
72
67
7F
72
67
5D
5D
5D
5D
7F
67
相關(guān)PDF資料
PDF描述
PCD3354A 8-bit microcontrollers with DTMF generator and 256 bytes EEPROM
PCA3354C 8-bit microcontrollers with DTMF generator and 256 bytes EEPROM
PCD3359A 8-bit microcontroller with DTMF generator and 128 bytes EEPROM
PCD3359AH 8-bit microcontroller with DTMF generator and 128 bytes EEPROM
PCD3359AP 8-bit microcontroller with DTMF generator and 128 bytes EEPROM
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