20-668-0011 Rabbit Semiconductor, 20-668-0011 Datasheet - Page 54

• 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

5.3 Operation
5.3.1 Memory Management Unit (MMU)
Code execution takes place in the 64 KB logical memory space, which is divided into four
segments: root, data, stack, and extended (XMEM). The root segment is always mapped
starting at physical address 0x00000, but the other segments can be remapped to start at
any physical 4 KB block boundary.
The data and stack segment mappings are set by writing to the appropriate register, as
shown in Table 5-1. The DATASEG and STACKSEG registers provide backwards
compatibility to the Rabbit 2000 processor.
Each of these registers provides a 4 KB offset that is added to the logical address to pro-
vide a physical address as shown in Figure 5-3.
44
DATASEG
STACKSEG
XPC
Register
Table 5-1. Memory Management Registers
Figure 5-3. MMU Operation
Segment
XMEM
Stack
Data
8 bits
8 bits
8 bits
Size
Loaded via instructions
LD XPC,A and LD A,XPC
Rabbit 3000 Microprocessor User’s Manual
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