HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 257

• Manufacturer Part Number: HD6417021
• Description: SuperH RISC engine
• Manufacturer: Hitachi Semiconductor

10.3.2
All registers other than the TCNT, general registers, and buffer registers are 8-bit registers. These
are connected to the CPU by an 8-bit data bus. Figures 10.12 and 10.13 illustrate reading and
writing in byte units with the timer control register (TCR). These registers must be accessed by
byte access.
CPU
CPU
CPU
8-Bit Accessible Registers
Internal data bus
Internal data bus
Internal data bus
H
H
H
L
L
L
Figure 10.10 Accessing TCNT (TCNT–CPU (upper byte))
Figure 10.11 Accessing TCNT (TCNT–CPU (lower byte))
Figure 10.9 Accessing TCNT (CPU–TCNT (lower byte))
interface
interface
interface
Bus
Bus
Bus
TCNTH
TCNTH
TCNTH
TCNTL
TCNTL
TCNTL
H
H
H
L
L
L
Module
data bus
Module
data bus
Module
data bus
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