20-668-0011 Rabbit Semiconductor, 20-668-0011 Datasheet - Page 284

• 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

B.1.3 Revision-Level ID Register
Two read-only registers are provided to allow software to identify the Rabbit microproces-
sor and recognize the features and capabilities of the chip. Five bits in each of these regis-
ters are unique to each version of the chip. One register identifies the CPU (GCPU), and
the other register is reserved for revision identification (GREV). The CPU identification
(GCPU) of all revisions of the Rabbit 3000 microprocessor is the same. Rabbit 3000 revi-
sions are differentiated by the value in the GREV register.
Table B-5 summarizes the processor identification information for the different Rabbit
3000 versions.
B.1.4 System/User Mode
By default, all of the hardware is accessible by the programmer. However, if a control bit
in the Enable Dual Mode Register (EDMR) is set to one, two operating modes, System
and User, become available. The System mode is just like the normal operating mode, but
the User mode restricts program access to the hardware and to the System mode. Individ-
ual peripherals may be enabled for User mode access in the User Enable registers listed
below. When enabled for User mode access, a peripheral interrupt (if it is capable of gen-
erating an interrupt) can only be requested at interrupt priority level -2 or -1, and it is
assumed that the interrupt service routine will be executed by User mode code. Note that
the processor automatically enters the System mode when entering the ISR area in
response to an interrupt, and the User mode must be specifically entered before continuing
with the interrupt service routine. The System/User mode is discussed in great detail in
Chapter 26.
274
Table B-5. Rabbit 3000 Revision Identification Information
Rabbit 3000
Rabbit 3000A
Processor Revision
IL1T, IZ1T
IL2T, IZ2T
Identifier
Package
Rabbit 3000 Microprocessor User’s Manual
GCPU
00001
00001
[4:0]
GREV
00000
00001
[4:0]