20-668-0024 Rabbit Semiconductor, 20-668-0024 Datasheet - Page 29

• Manufacturer Part Number: 20-668-0024
• Description: IC CPU RABBIT4000 128-LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 20-668-0024

• Processor Type: Rabbit 4000 8-bit
• Speed: 60MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Other names: 20-668-0022; 316-1078

The 32 kHz oscillator can be used to drive as the processor and peripheral clock to provide
significant power savings in “ultra-sleepy” modes. The 32 kHz oscillator can be divided
by 2, 4, 8, or 16 to provide clock speeds as low as 2.048 kHz. Special self-timed chip
selects are available to keep the memory devices enabled for as short a time as possible
when an ultra-sleepy mode is enabled; see Chapter 26 for more details on reducing power
consumption.
When the 32 kHz clock is enabled, the periodic interrupt is disabled automatically. The
real-time clock and watchdog timers keep running, and use the full 32 kHz clock even
when the processor and peripheral clocks use a divider on the 32 kHz clock.
Chapter 2 Clocks
Table 2-4. Ultra-Sleepy Clock Modes
xxxxx000
xxxxx100
xxxxx101
xxxxx110
xxxxx111
GPSCR
Setting
Peripheral Clock
Processor and
32.768 kHz
16.384 kHz
8.192 kHz
4.096 kHz
2.048 kHz
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