R01UH0822EJ0100 Rev.1.00
Page 555 of 1041
Jul 31, 2019
RX13T Group
20. Port Output Enable 3 (POE3C)
20.4
POE Setting Procedure
shows the procedure for setting the POE. It illustrates an example of high-impedance control in response to
comparison of the output levels on the MTU3 pins (MTIOC3B/MTIOC3D). In the figure, P71 is used as the MTIOC3B
pin and P74 is used as the MTIOC3D pin.
Figure 20.7
Procedure for Setting the POE
20.5
Interrupts
The POE issues a request to generate an interrupt when the specified condition is satisfied during input-level detection or
output-level comparison.
shows the interrupt sources and their conditions.
Table 20.4
Interrupt Sources and Conditions
Name
Interrupt Source
Interrupt Flag
Condition
OEI1
Output enable interrupt 1
When the ICSR1.POE0F flag becomes 1 while the
ICSR1.PIE1 bit is 1 or when the OCSR1.OSF1 flag becomes 1
while the OCSR1.OIE1 bit is 1
OEI3
Output enable interrupt 3
When the ICSR3.POE8F flag becomes 1 while the
ICSR3.PIE3 bit is 1
OEI4
Output enable interrupt 4
When the ICSR4.POE10F flag is set to 1 while the
ICSR4.PIE4 bit is 1
[1]
Start
Set the ALR1.OLSG0A and OLSG0B bits
to 0, and the ALR1.OLSEN bit to 1.
Set the POECR2.MTU3BDZE bit to 1.
Make the setting to operate MTU3.
End
[2]
[3]
Set the MTU3 pins (P71 and P74) for the peripheral function by the
PMR register of the I/O port before making the following settings.
[1] Set the ALR1.OLSG0A and OLSG0B bits to 0 and the
ALR1.OLSEN bit to 1 to set MTIOC3B and MTIOC3D pins as
active low.
[2] Set the POECR2.MTU3BDZE bit to 1 to enable high-impedance
control on the MTIOC3B and MTIOC3D pins.
[3] Make the setting to operate MTU3 pin.
After the above settings, if MTIOC3B (P71) and MTIOC3D (P74)
pins are simultaneously at the low level, then the pins become high-
impedance and the OCSR1.OSF1 flag is set to 1.
For the method for releasing high-impedance, refer to section
20.3.7, Recover from High-Impedance State.