D12320VF25V Datasheet, PDF (249/1146 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 7 Data Transfer Controller
7.4 Interrupts
An interrupt request is issued to the CPU when the DTC finishes the specified number of data
transfers, or a data transfer for which the DISEL bit was set to 1. In the case of interrupt
activation, the interrupt set as the activation source is generated. These interrupts to the CPU are
subject to CPU mask level and interrupt controller priority level control.
In the case of activation by software, a software activated data transfer end interrupt (SWDTEND)
is generated.
When the DISEL bit is 1 and one data transfer has ended, or the specified number of transfers
have ended, after data transfer ends, the SWDTE bit is held at 1 and an SWDTEND interrupt is
generated. The interrupt handling routine should clear the SWDTE bit to 0.
When the DTC is activated by software, an SWDTEND interrupt is not generated during a data
transfer wait or during data transfer even if the SWDTE bit is set to 1.
7.5 Usage Notes
Module Stop: When the MSTP14 bit in MSTPCR is set to 1, the DTC clock stops, and the DTC
enters the module stop state. However, 1 cannot be written to the MSTP14 bit while the DTC is
operating.
On-Chip RAM: The MRA, MRB, SAR, DAR, CRA, and CRB registers are all located in on-chip
RAM. When the DTC is used, the RAME bit in SYSCR must not be cleared to 0.
DTCE Bit Setting: 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.
Chain Transfer: When chain transfer is used, clearing of the activation source or DTCER is
performed when the last of the chain of data transfers is executed. SCI and A/D converter
interrupt/activation sources, on the other hand, are cleared when the DTC reads or writes to the
prescribed register.
Therefore, when the DTC is activated by an interrupt or activation source, if a read/write of the
relevant register is not included in the last chained data transfer, the interrupt or activation source
will be retained.
Rev.7.00 Feb. 14, 2007 page 215 of 1108
REJ09B0089-0700