Features
• Control Unit
o 16-bit instruction decoding
o Repeat instructions for efficient use
of program space and enhanced
execution
• Central Arithmetic-Logic Unit
o 16-bit parallel shifter; 32-bit
arithmetic and logical operations
o 16 x 16 bit parallel multiplier with a
32-bit product
o 32-bit accumulator with output
shifter
o Single-cycle Multiply-and-
Accumulate instructions
• Auxiliary Registers
o 8 16-bit registers for indirect
addressing or temporary data
storage
o 16-bit Auxiliary Register Arithmetic
Unit including operations with
reversed-carry propagation
• Memory addressing modes
o Direct - using a 9-bit Page Pointer
and instruction word’s lowest 7-bits
o Indirect – using the Auxiliary
Register File
o Immediate – less than 16-bit via
instruction word or full 16-bit long
immediate following the instruction
word
o Block moves for data/program
management
• 8-level Hardware Stack
• Interrupt Controller: 6 interrupt sources,
excluding reset and a software interrupt
• Synchronous serial port for direct codec
interface
• 16-bit reload timer
• Program Memory organization
CAST, Inc.
C32025 Megafunction Datasheet
o 4K-words of internal ROM
o Internal 256-word RAM block
configurable either as program or
data space
o 64K-word external program space
• Data Memory organization
o 2 Internal 256-word and one 32-
word RAM blocks
o 64K-words of external data space
o 6 memory mapped registers
• 16 Input and 16 Output channels
• Wait states for interfacing slower off-chip
devices
• Multiprocessing support
o Global data memory interface
o Synchronization input for
synchronous multiprocessor
configurations
• Concurrent DMA using an extended Hold
operation
• Design is strictly synchronous with positive-
edge clocking and synchronous reset, no
internal tri-states.
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