HD6433802H Datasheet, PDF (209/435 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

2. Read access
In access to TCF, when the upper byte is read the upper-byte data is transferred directly to the
CPU and the lower-byte data is transferred to TEMP. Next, when the lower byte is read, the
lower-byte data in TEMP is transferred to the CPU.
In access to OCRF, when the upper byte is read the upper-byte data is transferred directly to the
CPU. When the lower byte is read, the lower-byte data is transferred directly to the CPU.
Figure 9.4 shows an example in which TCF is read when it contains H'AAFF.
Read upper byte
CPU
(H'AA)
Bus
interface
Module data bus
TEMP
(H'FF)
Read lower byte
CPU
(H'FF)
Bus
interface
TCFH
(H'AA)
TCFL
(H'FF)
Module data bus
TEMP
(H'FF)
TCFH
(AB)*
TCFL
(00)*
Note: * H'AB00 if counter has been updated once.
Figure 9.4 Read Access to TCF (TCF → CPU)
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