mc145201dt Freescale Semiconductor, Inc, mc145201dt Datasheet - Page 15

• Manufacturer Part Number: mc145201dt
• Description: 2.0 Ghz Pll Frequency Synthesizers
• Manufacturer: Freescale Semiconductor, Inc

MOTOROLA
NOTES:
ENB
CLK
D in
1. Bits R15 through R13 control the configurable “OSC or 4–stage divider” block (see Block Diagram).
2. Bits R12 through R0 control the “13–stage R counter” block (see Block Diagram).
3. A power–on initialize circuit forces a default REF in to REF out ratio of eight.
4. At this point, bits R13, R14, and R15 are stored and sent to the “OSC or 4–Stage Divider” block in the Block Diagram. Bits R0 through
5. At this point, bits R0 through R12 are transferred to the second buffer of the R register. The R counter begins dividing by the new ratio
6. Allows direct access to reference input of phase/frequency detectors.
0
1
2
3
4
5
6
7
R12 are loaded into the first buffer in the double–buffered section of the R register. Therefore, the R counter divide ratio is not altered
yet and retains the previous ratio loaded. The C and A registers are not affected.
after completing the rest of the present count cycle. CLK must be low during the ENB pulse, as shown. Also, see note 3 of Figure 16 for
an alternate method of loading the second buffer in the R register. The C and A registers are not affected. The first buffer of the R register
is not affected.
CRYSTAL MODE, SHUT DOWN
CRYSTAL MODE, ACTIVE
REFERENCE MODE, REF in ENABLED and REF out
REFERENCE MODE, REF out = REF in (BUFFERED)
REFERENCE MODE, REF out = REF in /2
REFERENCE MODE, REF out = REF in /4
REFERENCE MODE, REF out = REF in /8 (NOTE 3)
REFERENCE MODE, REF out = REF in /16
STATIC LOW
OCTAL VALUE
MSB
R15
1
R14
2
R13
Figure 17. R Register Access and Format (16 Clock Cycles Are Used)
3
R12
4
BINARY VALUE
R11
5
R10
6
R9
0
0
0
0
0
0
0
0
0
·
·
·
1
1
7
HEXADECIMAL VALUE
0
0
0
0
0
0
0
0
0
·
·
·
F
F
R8
8
0
0
0
0
0
0
0
0
0
·
·
·
F
F
R7
0
1
2
3
4
5
6
7
8
·
·
·
E
F
9
NOT ALLOWED
R COUNTER =
NOT ALLOWED
NOT ALLOWED
NOT ALLOWED
R COUNTER =
R COUNTER =
R COUNTER =
R COUNTER =
R COUNTER =
R COUNTER =
R6
10
R5
11
5
8
8190
1 (NOTE 6)
6
7
8191
R4
12
R3
13
R2
14
MC145200 MC145201
R1
15
R0
LSB
16
NOTE
4
NOTE
5
15