Section 2 CPU
2.1
Overview
The H8/300L CPU has sixteen 8-bit general registers, which can also be paired as eight 16-bit
registers. Its concise instruction set is designed for high-speed operation.
2.1.1
Features
Features of the H8/300L CPU are listed below.
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General-register architecture
Sixteen 8-bit general registers, also usable as eight 16-bit general registers
Instruction set with 55 basic instructions, including:
Multiply and divide instructions
Powerful bit-manipulation instructions
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Eight addressing modes
Register direct
Register indirect
Register indirect with displacement
Register indirect with post-increment or pre-decrement
Absolute address
Immediate
Program-counter relative
Memory indirect
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64-kbyte address space
High-speed operation
All frequently used instructions are executed in two to four states
High-speed arithmetic and logic operations
8- or 16-bit register-register add or subtract:
8 × 8-bit multiply:
0.67 µs*
4.67 µs*
4.67 µs*
16 ÷ 8-bit divide:
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Low-power operation modes
SLEEP instruction for transfer to low-power operation
Note: * These values are at ø = 3 MHz.
15
ETC [ ETC ]
