R01UH0823EJ0100 Rev.1.00 Page 427 of 1823
Jul 31, 2019
RX23W Group 20. Event Link Controller (ELC)
(7) Operation of the PDBFn Registers
(a) Input Port Groups
When an event signal is input to an input port group, the level of the corresponding pins is transferred to the PDBFn
register (n = 1, 2). When another event signal is input to the input port group in this condition, different operations are
performed depending on the PGCn.PGCOVE bit setting described as below.
When the PGCn.PGCOVE bit is 0 (overwriting is disabled)
When the value transferred to the PDBFn register after an input of the last event signal has already been read by the
CPU or DTC, the level of the corresponding pins at the time is transferred to the PDBFn register. When the value
has not been read, the level of the pins is not transferred to the PDBFn register, and the input event signal is ignored.
When the PGCn.PGCOVE bit is 1 (overwriting is enabled)
When another event signal is input to the input port group, the level of the corresponding pins is transferred to the
PDBFn register.
(b) Output Port Groups
When an output port group is specified to output the PDBFn register value (PGCn.PGCO[2:0] bits = 011b), the PDBFn
register value is transferred to the PODR register following an input of an event signal to the output port group. Data is
not transferred to the bits corresponding to the ports that are not specified as members of the output port group.
When output data is specified to rotate in an output port group (PGCn.PGCO[2:0] bits = 1xxb), the data is transferred
from the PDBFn register to the PODR register at first event signal, and the PODR register value is rotated from MSB to
LSB within the relevant group at second and subsequent signals.
Examples of operation are shown in
Figure 20.6.
Figure 20.6 Bit-Rotating Operation of Output Port Groups (Port B)
PDBF1 register
PORTB.PODR register
PB3
PB2
PB1
PB0
Specified as an
output port group
00001000b
xxxx0000b xxxx1000b
transferred
xxxx1000b xxxx0100b xxxx0010b xxxx0001b
Event signal
rotated
Event signal Event signal Event signal Event signalEvent signal
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