
■ SuperH Architecture:
Common Features
RISC-type instruction set
• Instruction length: fixed
16-bit-long instructions for
improved code efficiency
• Load-store architecture
(basic arithmetic and logic
operations are carried out
between registers)
• Delayed unconditional branch
instructions reduce pipeline
disruption
• Instruction set optimized for
the C language
4
SuperH
®
Family of Microcontrollers & Microprocessors
R0
31 0
31 0
R1
R0
31 0
31
0
R1
R2
R7
R2
SR: Status Register
GBR: Global Base Register
General Register
Control Register
System Register
Program Counter
R14
R15
R7
MD RR RI M Q I I I I . . S T
31 0
31 0
MACH: Multiply and Accumulator High
MACL: Multiply and Accumulator Low
: Accessible only in Privilege mode (SH-3 and SH-4 only)
PR: Procedure Register
PC: Program Counter
•
•
•
•
•
•
-
-
-
-
-
-
•
•
•
SSR: Saved Status Register
31
0
SPC: Saved Program Counter
VBR: Vector Base Register
Code
compatibility
Code
compatibility
SH-4A
103 instructions
FPU, Cache operations
SH-4
91 instructions
Single/double-precision FPU
SH-3
68 instructions
MMU Control
SH-2
62 instructions
32-bit MAC
SH-1
56 instructions
SH3-DSP
160 instructions
92 DSP instructions
SH2-DSP
154 instructions
92 DSP instructions
Code
compatibility
SH-2A
91 instructions
Enhanced shift, bit,
& divide operations
112 Instructions
with FPU
Mixed
16-/32-bit length
Fixed
16-bit length
Mixed
16-/32-bit length
SuperH Instruction Set
SuperH Programming Model
CPU register set
• Sixteen 32-bit general-purpose
registers
• Up to 7 control registers and
4 system registers for fast jumps
and interrupt response
Efficient caching scheme
for each series
• LRU replacement policy
algorithm for improved hit rates
• Each family’s cache architecture
has been optimized for the best
latency/miss-rate balance:
e.g., SH-4A devices have
32KB + 32KB, 4-way
set-associative, separate
instruction and operand caches
for improved performance
Komentarze do niniejszej Instrukcji