2.1
Overview
The H8/300H CPU is a high-speed central processing unit with an internal 32-bit architecture that
is upward-compatible with the H8/300 CPU. The H8/300H CPU has sixteen 16-bit general
registers, can address a 16-Mbyte linear address space, and is ideal for realtime control.
2.1.1
Features
The H8/300H CPU has the following features.
• Upward compatibility with H8/300 CPU
Can execute H8/300 Series object programs
• General-register architecture
Sixteen 16-bit general registers (also usable as sixteen 8-bit registers or eight 32-bit registers)
• 64 basic instructions
8/16/32-bit arithmetic and logic instructions
Multiply and divide instructions
Powerful bit-manipulation instructions
• Eight addressing modes
Register direct [Rn]
Register indirect [@ERn]
Register indirect with displacement [@(d:16, ERn) or @(d:24, ERn)]
Register indirect with post-increment or pre-decrement [@ERn+ or @–ERn]
Absolute address [@aa:8, @aa:16, or @aa:24]
Immediate [#xx:8, #xx:16, or #xx:32]
Program-counter relative [@(d:8, PC) or @(d:16, PC)]
Memory indirect [@@aa:8]
• 16-Mbyte linear address space
• High-speed operation
All frequently-used instructions execute in two to four states
Maximum clock frequency:
8/16/32-bit register-register add/subtract: 80 ns@25 MHz
8 × 8-bit register-register multiply:
16 ÷ 8-bit register-register divide:
16 × 16-bit register-register multiply:
32 ÷ 16-bit register-register divide:
Section 2 CPU
25 MHz
560 ns@25 MHz
560 ns@25 MHz
880 ns@25 MHz
880 ns@25 MHz
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