3825_03 Datasheet, PDF (112/339 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.3 Timer X and timer Y
(5) Real time port control
The real time port control is the function which
outputs preset data from the real time ports in
synchronization with an underflow of the X coun-
ter. Table 2.3.1 shows real time ports and bits
for storing data. This real time port control func-
tion is available in every mode.
A data output from the real time port is started
at setting the real time port control bit to “1”
(when setting “1” to the real time port control
bit of the timer X mode register, use the SEB
instruction).
When the data for real time port is rewritten,
the rewritten values are output at the first
underflow of the X counter after rewritting.
Figure 2.3.5 shows a timer mode operation
example with the real time port function.
The real time port is also used as port P52 and
P53. When using the real time port, set the
corresponding bit of the port P5 direction reg-
ister (address 000B16) to “1” for the output mode.
Table 2.3.1 Real time ports and bits for storing data
Real time port
RTP0 (P52)
RTP1 (P53)
Bit for storing data
Bit 2 of timer X mode register
Bit 3 of timer X mode register
2–40
3825 GROUP USER’S MANUAL