Cpu Interface; 8-Bit Registers - Hitachi H8/3006 Hardware Manual

10.3

CPU Interface

10.3.1

8-Bit Registers

8TCNT, TCORA, TCORB, 8TCR, and 8TCSR are 8-bit registers. These registers are connected
to the CPU by an internal 16-bit data bus and can be read and written a word at a time or a byte at
a time.
Figures 10.2 and 10.3 show the operation in word read and write accesses to 8TCNT.
Figures 10.4 to 10.7 show the operation in byte read and write accesses to 8TCNT0 and 8TCNT1.
Internal data bus
H
C
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P
U
Figure 10.2 8TCNT Access Operation (CPU Writes to 8TCNT, Word)
Internal data bus
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C
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Figure 10.3 8TCNT Access Operation (CPU Reads 8TCNT, Word)
Internal data bus
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C
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Figure 10.4 8TCNTH Access Operation (CPU Writes to 8TCNTH, Upper Byte)
Bus
interface
Bus
interface
Bus
interface
8TCNT0 8TCNT1
8TCNT0 8TCNT1
8TCNT0 8TCNT1
H
Module data bus
L
H
Module data bus
L
H
Module data bus
L
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