R01UH0823EJ0100 Rev.1.00
Page 385 of 1823
Jul 31, 2019
RX23W Group
19. Data Transfer Controller (DTCa)
19.2.6
DTC Transfer Count Register B (CRB)
CRB register is used to set the block transfer count for block transfer mode and cannot be accessed directly from the
CPU.
The transfer count is 1, 65535, and 65536 when the set value is 0001h, FFFFh, and 0000h, respectively.
The CRB value is decremented (–1) when the final data of a single block size is transferred.
When normal transfer mode or repeat transfer mode is selected, this register is not used and the set value is ignored.
19.2.7
DTC Control Register (DTCCR)
DTCCR register is used to control the DTC operation.
RRS Bit (DTC Transfer Information Read Skip Enable)
The DTC vector number is compared with the vector number in the previous data transfer.
When these vector numbers match and the RRS bit is set to 1, DTC data transfer is performed without reading the
transferred information. However, when the previous transfer was chain transfer, the transferred information is read
regardless of the value of the RRS bit.
Furthermore, when the transfer counter (CRA register) became 0 during the previous normal transfer and when the
transfer counter (CRB register) became 0 during the previous block transfer, the transferred information is read
regardless of the RRS bit value.
Address(es): (inaccessible directly from the CPU)
b15
b14
b13
b12
b11
b10
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
Value after reset:
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x: Undefined
Address(es): DTC.DTCCR 0008 2400h
b7
b6
b5
b4
b3
b2
b1
b0
—
—
—
RRS
—
—
—
—
Value after reset:
0
0
0
0
1
0
0
0
Bit
Symbol
Bit Name
Description
R/W
b2 to b0
—
Reserved
These bits are read as 0. The write value should be 0.
R/W
b3
—
Reserved
This bit is read as 1. The write value should be 1.
R/W
b4
DTC Transfer Information
Read Skip Enable
0: Transfer information read is not skipped.
1: Transfer information read is skipped when vector numbers match.
R/W
b7 to b5
—
Reserved
These bits are read as 0. The write value should be 0.
R/W