20-668-0011 Rabbit Semiconductor, 20-668-0011 Datasheet - Page 229

• 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

Figure 26-3 shows an overview of this level of operation.
26.3.4 Enabling the System/User Mode
The following steps describe how to enable the System/User Mode.
1. If a peripheral needs to be accessed while in User Mode, write to the appropriate user
2. Write a 1 to bit 0 of EDMR to enable System/User Mode.
3. Execute the SETUSR instruction to enter User Mode.
After the User Mode is entered, the limitations described earlier are in effect — writes to
protected registers will be ignored, Priority 3 is not available, and executing an IDET will
cause a System Mode Violation interrupt. Other features such as write protection may be
in effect for the User Mode as well.
Chapter 26 System/User Mode
enable register to allow that access.
Figure 26-3. System/User Mode Setup for Operating System
System Mode
SYSCALL
Flash file
Interrupt
handlers
handler
system
Return from interrupts
SYSCALL, RST
Interrupts,
User Mode
User-defined
Application
interrupts
code
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