Hitachi H8/3937 Series Hardware Manual page 220

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
CPU
(H'AA)
Read lower byte
CPU
(H'FF)
Note: * H'AB00 if counter has been updated once.
208
Bus
interface
Bus
interface
Figure 9-5 Read Access to TCF (TCF → CPU)
Module data bus
TEMP
(H'FF)
TCFH TCFL
(H'AA) (H'FF)
Module data bus
TEMP
(H'FF)
TCFH TCFL
(AB)* (00)*