8-Bit Accessible Registers - Hitachi H8/3008 Hardware Manual

On-chip data bus
H
CPU L
Figure 8.9 Access to Timer Counter L (CPU Reads 16TCNTL, Lower Byte)
8.3.2

8-Bit Accessible Registers

The registers other than the timer counters and general registers are 8-bit registers. These registers
are linked to the CPU by an internal 8-bit data bus.
Figures 8.10 and 8.11 show examples of byte read and write access to a 16TCR.
If a word-size data transfer instruction is executed, two byte transfers are performed.
On-chip data bus
H
CPU L
On-chip data bus
H
CPU L
Bus interface
Bus interface
Figure 8.10 16TCR Access (CPU Writes to 16TCR)
Bus interface
Figure 8.11 16TCR Access (CPU Reads 16TCR)
16TCNTH 16TCNTL
16TCR
16TCR
H
Module
L
data bus
H
Module
L
data bus
H
Module
L
data bus
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