
MC12210
5
MOTOROLA RF/IF DEVICE DATA
PROGRAMMABLE DIVIDER
19–bit serial data format for the programmable divider is shown below. If the control bit is LOW, data is transferred from the 18–bit
shift register into the 18–bit latch which specifies the swallow A–counter divide ratio (0 to 127) and the programmable N–counter
divide ratio (16 to 2047). An N–counter divide ratio less than 16 is prohibited.
For Control bit (C) = LOW:
SETTING BITS FOR
DIVIDE RATIO OF
SWALLOW A–COUNTER
C
A
1
A
2
A
3
A
4
A
5
A
6
A
7
N
8
N
9
N
10
N
11
N
12
N
13
N
14
N
15
LSB
MSB (FIRST BIT)
CONTROL BIT (LAST BIT)
N
16
N
17
N
18
SETTING BITS FOR
DIVIDE RATIO OF
PROGRAMMABLE N–COUNTER
DIVIDE RATIO OF PROGRAMMABLE N–COUNTER
DIVIDE RATIO OF SWALLOW A–COUNTER
Divide
Ratio N
N
18
N
17
N
16
N
15
N
14
N
13
N
12
N
11
N
10
N
9
N
8
Divide
Ratio A
A
7
A
6
A
5
A
4
A
3
A
2
A
1
16
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
17
0
0
0
0
0
0
1
0
0
0
1
1
0
0
0
0
0
0
1
2047
1
1
1
1
1
1
1
1
1
1
1
127
1
1
1
1
1
1
1
DIVIDE RATIO SETTING
fvco = [(P
N)+A]
fosc
÷
R with A<N
fvco: Output frequency of external voltage controlled oscillator (VCO)
N:
Preset divide ratio of binary 11–bit programmable counter (16 to 2047)
A:
Preset divide ratio of binary 7–bit swallow counter (0 to 127, A<N)
fosc: Output frequency of the external frequency oscillator
R:
Preset divide ratio of binary 14–bit programmable reference counter (8 to 16383)
P:
Preset mode of dual modulus prescaler (32 or 64)
Figure 2. Serial Data Input Timing
N18:MSB
N17
(SW:MSB)
(R14)
N8
A7
(R7)
(R6)
A1
C = CONTROL BIT (LAST BIT)
(R1)
(C = CONTROL BIT (LAST BIT))
ts(D)
th(D)
tCW
ts(C
→
LE)
tEW
DATA
CLK
LE
NOTES:Programmable reference divider data shown in parenthesis. Data shifted into register on rising edge of CLK.
ts(D) = Setup Time DATA to CLK
th(D) = Hold Time DATA to CLK
tCW = CLK Pulse Width
tEW = LE Pulse Width
ts(C
→
LE) = Setup Time CLK to LE
ts(D)
≥
10 ns
th(D)
≥
20 ns
tCW
≥
30 ns
tEW
≥
20 ns
ts(C
→
LE)
≥
30 ns