HD64F2357F20V Datasheet, PDF (400/1049 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-chip Microcomputer H8S Family / H8S/2300 Series

10.3.2 8-Bit Registers
Registers other than TCNT and TGR are 8-bit. As the data bus to the CPU is 16 bits wide, these registers can be read and
written to in 16-bit units. They can also be read and written to in 8-bit units.
Examples of 8-bit register access operation are shown in figures 10-3 to 10-5.
Bus
master
Internal data bus
H
L
Bus interface
Module
data bus
TCR
Figure 10-3 8-Bit Register Access Operation [Bus Master ↔ TCR (Upper 8 Bits)]
Internal data bus
H
Bus
master ^L
Bus interface
Module
data bus
TMDR
Figure 10-4 8-Bit Register Access Operation [Bus Master ↔ TMDR (Lower 8 Bits)]
Internal data bus
H
Bus
master ^L
Bus interface
Module
data bus
TCR
TMDR
Figure 10-5 8-Bit Register Access Operation [Bus Master ↔ TCR and TMDR (16 Bits)]
Rev.6.00 Oct.28.2004 page 370 of 1016
REJ09B0138-0600H