R01UH0822EJ0100 Rev.1.00
Page 275 of 1041
Jul 31, 2019
RX13T Group
16. Data Transfer Controller (DTCb)
16.4.10
Sequence Transfer
A sequence transfer can be executed on the request source that is specified in the DTCSQE register. A sequence transfer
is started by setting the MRB.INDX bit to 1 and ended by setting the MRB.SQEND bit to 1. Setting the
DTCOR.SQTFRL bit to 1, even during a sequence transfer, forcibly ends the transfer and the next DTC transfer request
starts new sequence transfer with reference to the index table.
A sequence transfer includes the following processing.
(1) The first data transfer is executed by referring to the DTC vector table in response to a DTC transfer request from
the source specified in the DTCSQE register.
(2) The DTC index table is referred based on the value of the lower 8 bits of the first data transferred data in (1)
(sequence number).
(3) The transfer information is read from the address obtained from the DTC index table.
(4) A data transfer is executed in accordance with the transfer information. On completion of the data transfer, either
one of the following operations is performed by using the values of bits MRB.CHNE and MRB.SQEND.
•
A chain transfer is executed when the CHNE bit is 1. The next transfer information is read. Go to (4).
•
The sequence transfer is suspended when the CHNE bit is 0 and the SQEND bit is 0. Go to (5).
•
The sequence transfer ends when the CHNE bit is 0 and the SQEND bit is 1.
(5) When a DTC transfer request from the source specified in the DTCSQE register is accepted, the suspended
sequence transfer is resumed and the next transfer information is read. Go to (4).
Note 1. When the ICU.DTCERn.DTCE bit becomes 0 based on the result of the data transfer, a DTC transfer request is
not generated. Set the DTCE bit to 1 to resume sequence transfer. Refer to Figure 16.5 or section 14, Interrupt
Controller (ICUb) for the conditions where the DTCE bit becomes 1.
and
shows a basic sequence transfer operation.
Figure 16.15
Start and Suspension of Sequence Transfer
Start address of
transfer information
DTC vector address
DTC vector table
Transfer information
INDX = 1
(Start sequence transfer)
Transfer information
Data
Sequence number = p
Start address of sequence
DTC index table
DTC index address
Transfer information
CHNE = 1
SQEND = 0
Transfer information
Transfer information
CHNE = 0
SQEND = 0
n × 4
p × 4
(Suspend sequence transfer)