HD64F2149 Datasheet, PDF (203/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

For DTCE bit setting, read/write operations must be performed using bit-manipulation instructions
such as BSET and BCLR. For the initial setting only, however, when multiple activation sources
are set at one time, it is possible to disable interrupts and write after executing a dummy read on
the relevant register.
7.2.8 DTC Vector Register (DTVECR)
Bit
Initial value
Read/Write
7
6
5
4
3
2
1
0
SWDTE DTVEC6 DTVEC5 DTVEC4 DTVEC3 DTVEC2 DTVEC1 DTVEC0
0
0
0
0
0
0
0
0
R/(W)* R/W R/W R/W R/W R/W R/W R/W
Note: * A value of 1 can always be written to the SWDTE bit, but 0 can only be written after 1
is read.
DTVECR is an 8-bit readable/writable register that enables or disables DTC activation by
software, and sets a vector number for the software activation interrupt.
DTVECR is initialized to H'00 by a reset and in hardware standby mode.
Bit 7—DTC Software Activation Enable (SWDTE): Specifies enabling or disabling of DTC
software activation. To clear the SWDTE bit by software, read SWDTE when set to 1, then write 0
in the bit.
Bit 7
SWDTE
0
1
Description
DTC software activation is disabled
[Clearing condition]
When the DISEL bit is 0 and the specified number of transfers have
not ended
DTC software activation is enabled
[Holding conditions]
• When data transfer ends with the DISEL bit set to 1
• When the specified number of transfers end
• During software-activated data transfer
(Initial value)
Bits 6 to 0—DTC Software Activation Vectors 6 to 0 (DTVEC6 to DTVEC0): These bits
specify a vector number for DTC software activation.
The vector address is H'0400 + (vector number) << 1 (where << 1 indicates a 1-bit left shift). For
example, if DTVEC6 to DTVEC0 = H'10, the vector address is H'0420.
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