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 9-5 shows an example in which TCF is read when it contains H'AAFF.
Read upper byte
Module data bus
Bus
interface
CPU
(H'AA)
TEMP
(H'FF)
TCFH
(H'AA)
TCFL
(H'FF)
Read lower byte
Module data bus
Bus
interface
CPU
(H'FF)
TEMP
(H'FF)
TCFH
(AB)*
TCFL
(00)*
Note: * H'AB00 if counter has been updated once.
Figure 9-5 Read Access to TCF (TCF Æ CPU)
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ETC [ ETC ]
