MC44824 Datasheet, PDF (5/8 Pages) Motorola, Inc – TV AND VCR PLL TUNING CIRCUITS WITH 1.3 GHz PRESCALER AND I2C BUS

MC44824/25
Figure 3. Complete Data Transfer Process
SDA
SCL
S
1–7
8
9
STA ADDRESS R/W ACK
CA
1–7
8
9
DATA
ACK
1–7
8
DATA
9
P
ACK STO
Figure 4 shows the five bytes of information that are
needed for circuit operation: there is the chip address, two
bytes of control and band information and two bytes of
frequency information.
After the chip address, two or four data bytes may be
received: if three data bytes are received, the third data byte
is ignored.
If five or more data bytes are received, the fifth and
following data bytes are ignored and the last acknowledge
pulse is sent at the end of the fourth data byte.
The first and the third data bytes contain a function bit
which allows the IC to distinguish between frequency
information and control plus band information.
Frequency information is preceded by a Logic “0”. If the
function bit is Logic “1” the two following bytes contain control
and band information. The first data byte, shifted after the
chip address, may be byte CO or byte FM.
The two permissible bus protocols with five bytes are
shown in Figure 4.
CA_Chip Address
CO_Information
BA_Band Information
FM_Frequency Information
FL_Frequency Information
Figure 4. Definition of Bytes
ÉÉÉɹ ÉÉÉɹÉÉÉÉÉÉ⁰ ÉÉÉÉ⁰ÉÉÉÉÉÉ⁰ ÉÉÉÉ^0/1ÉÉÉÉ⁰ÉÉ^/1 ÉÉÉÉ⁰ÉÉÉÉ^AÉÉ^CK ÉÉ
1
T14
T13
T12
T11
T10
T9
T8
ACK
ÉÉÉÉ^B7ÉÉÉÉ^XÉÉÉÉÉÉ^X ÉÉÉÉ^B4ÉÉ^* ÉÉÉÉ^X ÉÉÉÉ^B2ÉÉÉÉÉÉ^B1 ÉÉÉÉ^B0ÉÉ^* ÉÉ^AÉÉ^CK ÉÉ
0
N14
N13
N12
N11
N10
N9
N8
ACK
N7
N6
N5
N4
N3
N2
N1
N0
ACK
CA_Chip Address
FM_Frequency Information
FL_Frequency Information
CO_Information
1
1
0
0
0
0/1
0/1
0
ACK
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ₀
N14
N13
N12
N11
N10
N9
N8
ACK
N7
N6
N5
N4
N3
N2
N1
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ ₁
T14
T13
T12
T11
T10
T9
N0
ACK
T8
ACK
BA_Band Information
B7
X
X
B4*
X
B2
B1
B0*
ACK
* B0 and B4 are only available on MC44825. On MC44824 this data is random.
Chip Address
The chip address is programmable by Pin 7 (8), CA.
CA – Pin 7 (8)
Address (HEX.)
Gnd to 0.1 VCC1
C0
Open or 0.2 VCC1 to 0.3 VCC1
C2
0.4 VCC1 to 0.7 VCC1
C4
0.8 VCC1 to 1.1 VCC1
C6
Bits B0, B1, B2, B4, B7: Control the Band Buffers
B0, B1, B2, B4, B7 = 0
B0, B1, B2, B4, B7 = 1
Buffer “Off”
Buffer “On”
Bit T8: Controls the Output of the Operational Amplifier
T8 = 0
Normal Operation
Operational Amplifier Active
T8 = 1
Output State of Operational Amplifier Switched “Off”,
Output Pulls High Through an External Pull–Up
Resistor
Bits T9, T12: Control the Phase Comparator
T9
T12
Function
1
0
Normal Operation
1
1
High Impedance
0
0
Upper Source “On” Only
0
1
Lower Source “On” Only
MOTOROLA ANALOG IC DEVICE DATA
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