20-668-0011 Rabbit Semiconductor, 20-668-0011 Datasheet - Page 23

• Manufacturer Part Number: 20-668-0011
• Description: IC MPU RABIT3000A 55.5MHZ128LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 20-668-0011

• Processor Type: Rabbit 3000 8-Bit
• Speed: 55.5MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 55.5 MHz
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 55 C
• Number Of Programmable I/os: 56
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 316-1061

2.3.3 Clock Doubler
The clock doubler allows a lower frequency crystal to be used for the main oscillator and
to provide an added range over which the clock frequency can be adjusted. The clock dou-
bler is controlled via the Global Clock Double Register (GCDR).
The clock doubler uses an on-chip delay circuit that must be programmed by the user at
startup if there is a need to double the clock. Table 2-3 lists the recommended delays for
the GCDR for various oscillator frequencies.
Chapter 2 Clocks
Table 2-3. Recommended Delays Set In GCDR for Clock Doubler
Recommended GCDR Value
0x000B
0x000F
0x0009
0x0006
0x0003
0x0000
11.0592–16.5888 MHz
16.5888–20.2752 MHz
20.2752–52.8384 MHz
7.3728–11.0592 MHz
Frequency Range
>52.8384 MHz
7.3728 MHz
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