HD64F2168 Datasheet, PDF (194/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

7.2.5 DTC Transfer Count Register A (CRA)
CRA is a 16-bit register that designates the number of times data is to be transferred by the DTC.
In normal mode, the entire CRA functions as a 16-bit transfer counter (1 to 65536). It is
decremented by 1 every time data is transferred, and transfer ends when the count reaches H'0000.
In repeat mode or block transfer mode, the CRA is divided into two parts; the upper eight bits
(CRAH) and the lower 8 bits (CRAL). CRAH holds the number of transfers while CRAL
functions as an 8-bit transfer counter (1 to 256). CRAL is decremented by 1 every time data is
transferred, and the contents of CRAH are sent when the count reaches H'00.
7.2.6 DTC Transfer Count Register B (CRB)
CRB is a 16-bit register that designates the number of times data is to be transferred by the DTC in
block transfer mode. It functions as a 16-bit transfer counter (1 to 65536) that is decremented by 1
every time data is transferred, and transfer ends when the count reaches H'0000.
7.2.7 DTC Enable Registers (DTCER)
DTCER specifies DTC activation interrupt sources. DTCER is comprised of five registers:
DTCERA to DTCERE. The correspondence between interrupt sources and DTCE bits is shown in
tables 7.1 and 7.4. For DTCE bit setting, use bit manipulation instructions such as BSET and
BCLR. Multiple DTC activation sources can be set at one time (only at the initial setting) by
masking all interrupts and writing data after executing a dummy read on the relevant register.
Bit
7 to 0
Initial
Bit Name Value
DTCE7 to All 0
DTCE0
R/W Description
R/W DTC Activation Enable
Setting this bit to 1 specifies a relevant interrupt source
as a DTC activation source.
[Clearing conditions]
• When data transfer has ended with the DISEL bit in
MRB set to 1
• When the specified number of transfers have ended
These bits are not cleared when the DISEL bit is 0 and
the specified number of transfers have not been
completed
Rev. 3.00, 03/04, page 154 of 830