![background image](http://html2.mh-extra.com/html/rabbit/6000/6000_user-manual_3115352021.webp)
Rabbit 6000 User’s Manual
digi.com
21
2.3.2 Main PLL
The main PLL is optimally tuned for a 25 MHz clock input and to produce a 400 MHz output, which can
be fed directly to the Flexible Interface Modules (FIMs), and is divided by two to 200 MHz for processor
and peripheral operation. Note that the main PLL can be bypassed if lower frequencies are desired.
The main PLL is enabled in GCDR, but is not selected as the main clock until enabled in MSCR. If the 32
kHz clock is present, then the switchover to the PLL output for the main clock will not occur until 200 µs
after the bit is enabled in MSCR to allow the PLL output to stabilize. The status of the main PLL (stable
output or not) can be read in bit 0 of MSSR.
The main PLL input clock is restricted to 20–200 MHz, and the output frequency range is limited to 300–
400 MHz. There are further restrictions on the internal frequency
The main PLL divider values are located in GCM0R and GCM1R. These should be set to a nonzero value
before enabling the PLL. Some suggested PLL settings are described in Table 2-3, chosen to match other
clock requirements in the design to allow clock sharing. If other PLL settings are desired, please contact
your sales representative at Digi International.
Note that if the PLL is enabled, restrictions may exist for the use of the spectrum spreader and clock dou-
bler. The following sections provide more details.
Table 2-3. Suggested PLL Modes
Input Clock
Main Clock
(max)
FIM Clock
(max)
GCM0R
Setting
GCM1R
Setting
20 MHz
150 MHz
300 MHz
xxx10000
xxxx0001
20 MHz
200 MHz
400 MHz
xxx10100
xxxx0001
25 MHz
150 MHz
300 MHz
xxx01100
xxxx0001
25 MHz
200 MHz
400 MHz
xxx10000
xxxx0001
48 MHz
156 MHz
312 MHz
xxx01101
xxxx0010
48 MHz
192 MHz
384 MHz
xxx10000
xxxx0010
Summary of Contents for 6000
Page 1: ...Rabbit 6000 Microprocessor User s Manual 90001108_J...
Page 11: ...Rabbit 6000 User s Manual digi com 11 1 3 Block Diagram Figure 1 1 Rabbit 6000 Block Diagram...
Page 43: ...Rabbit 6000 User s Manual digi com 43 4 1 1 Block Diagram...
Page 57: ...Rabbit 6000 User s Manual digi com 57 5 1 1 Block Diagram...
Page 88: ...Rabbit 6000 User s Manual digi com 88 7 2 Block Diagram...
Page 115: ...Rabbit 6000 User s Manual digi com 115 11 1 1 Block Diagram...
Page 127: ...Rabbit 6000 User s Manual digi com 127 12 1 1 Block Diagram...
Page 138: ...Rabbit 6000 User s Manual digi com 138 13 1 1 Block Diagram...
Page 154: ...Rabbit 6000 User s Manual digi com 154 15 1 1 Block Diagram...
Page 163: ...Rabbit 6000 User s Manual digi com 163 16 1 1 Block Diagram...
Page 170: ...Rabbit 6000 User s Manual digi com 170 17 1 1 Block Diagram...
Page 177: ...Rabbit 6000 User s Manual digi com 177 18 1 1 Block Diagram...
Page 186: ...Rabbit 6000 User s Manual digi com 186 19 1 1 Block Diagram...
Page 230: ...Rabbit 6000 User s Manual digi com 230 22 2 Block Diagram...
Page 234: ...Rabbit 6000 User s Manual digi com 234 Figure 22 3 Sample Slow A D Converter Circuit...
Page 287: ...Rabbit 6000 User s Manual digi com 287 25 1 1 Block Diagram...
Page 310: ...Rabbit 6000 User s Manual digi com 310 26 1 1 Block Diagram...
Page 323: ...Rabbit 6000 User s Manual digi com 323 28 1 1 Block Diagram...
Page 351: ...Rabbit 6000 User s Manual digi com 351 31 1 4 Block Diagram...
Page 361: ...Rabbit 6000 User s Manual digi com 361 32 1 1 Block Diagram...
Page 369: ...Rabbit 6000 User s Manual digi com 369 33 2 Block Diagram...
Page 390: ...Rabbit 6000 User s Manual digi com 390 35 1 1 Block Diagram...
Page 408: ...Rabbit 6000 User s Manual digi com 408...
Page 410: ...Rabbit 6000 User s Manual digi com 410...
Page 411: ...Rabbit 6000 User s Manual digi com 411...
Page 420: ...Rabbit 6000 User s Manual digi com 420 Figure 37 1 Memory Read and Write Cycles...