Rev. 1.50, 10/04, page 2 of 448
Item Features
Floatingpoint unit
(FPU)
•
On-chip floating-point coprocessor
•
Supports single-precision (32 bits) and double-precision (64 bits)
•
Supports IEEE754-compliant data types and exceptions
•
Two rounding modes: Round to Nearest and Round to Zero
•
Handling of denormalized numbers: Truncation to zero or interrupt
generation for IEEE754 compliance
•
Floating-point registers: 32 bits
×
16 words
×
2 banks
(single-precision
×
16 words or double-precision
×
8 words)
×
2 banks
•
32-bit CPU-FPU floating-point communication register (FPUL)
•
Supports FMAC (multiply-and-accumulate) instruction
•
Supports FDIV (divide) and FSQRT (square root) instructions
•
Supports FLDI0/FLDI1 (load constant 0/1) instructions
•
Instruction execution times
Latency (FADD/FSUB): 3 cycles (single-precision), 5 cycles (double-
precision)
Latency (FMAC/ FMUL): 5 cycles (single-precision), 7 cycles (double-
precision)
Pitch (FADD/FSUB): 1 cycle (single-precision/double-precision)
Pitch (FMAC/FMUL): 1 cycle (single-precision), 3 cycles (double-
precision)
Note:
FMAC is supported for single-precision only.
•
3-D graphics instructions (single-precision only):
4-dimensional vector conversion and matrix operations (FTRV): 4 cycles
(pitch), 8 cycles (latency)
4-dimensional vector (FIPR) inner product: 1 cycle (pitch), 5 cycles
(latency)
•
Ten-stage pipeline
Memory
management
unit (MMU)
•
4 Gbytes of physical address space, 256 address space identifiers (address
space identifier ASID: 8 bits)
•
Supports single virtual memory mode and multiple virtual memory mode
•
Supports multiple page sizes: 1 Kbyte, 4 Kbytes, 64 Kbytes, or 1 Mbyte
•
4-entry full associative TLB for instructions
•
64-entry full associative TLB for instructions and operands
•
Supports software selection of replacement method and random-counter
replacement algorithms
•
Contents of TLB are directly accessible through address mapping
Summary of Contents for SuperH SH-4A
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