R01UH0823EJ0100 Rev.1.00
Page 408 of 1823
Jul 31, 2019
RX23W Group
19. Data Transfer Controller (DTCa)
19.10 Usage Notes
19.10.1
Start Address of Transfer Information
Set multiples of 4 for the start addresses of the transfer information to be specified in the DTC vector table. If any value
other than a multiple of 4 is specified, access still proceeds with the lower 2 bits of the address regarded as 00b.
19.10.2
Allocating Transfer Information
Allocate transfer information in the memory area according to the endian of the area as shown in
.
For example, when writing CRA and CRB settings in 16-bit units in big endian, write the CRA setting to the address plus
8h (Ch) and the CRB setting to the address plus Ah (Eh). In little endian, write the CRB setting to the address plus 8h
(Ch) and the CRA setting to the address plus Ah (Eh). When writing CRA and CRB settings in 32-bit units, allocate the
CRA setting at the MSB side of the 32 bits and the CRB setting at the LSB side, and write the settings to the address plus
8h (Ch), regardless of endian.
Figure 19.16
Allocation of Transfer Information
1
0
MRA
SAR
MRB
DAR
CRA
CRB
3
2
Allocation of transfer information
to little-endian area
(Short-address mode)
4 bytes
Lower address
2
3
MRA
SAR
MRB
DAR
CRA
CRB
0
1
Allocation of transfer
information to big-endian area
(Short-address mode)
4 bytes
Lower address
Address
4n
4 (n + 1)
4 (n + 2)
1
0
MRA
SAR
MRB
DAR
CRA
CRB
3
2
Allocation of transfer information
to little-endian area
(Full-address mode)
4 bytes
Lower address
Address
4n
4 (n + 1)
4 (n + 2)
4 (n + 3)
2
3
MRA
SAR
MRB
DAR
CRA
CRB
0
1
Allocation of transfer
information to big-endian area
(Full-address mode)
4 bytes
Lower address
Reserved
(0000h)
Reserved
(0000h)
Address
4n
4 (n + 1)
4 (n + 2)
Address
4n
4 (n + 1)
4 (n + 2)
4 (n + 3)