Advertisement
9.4
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.
9.5
Usage Notes
Module Stop: When the MSTPA6 bit in MSTPCRA is set to 1, the DTC clock stops, and the
DTC enters the module stop state. However, 1 cannot be written in the MSTPA6 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.
DMAC Transfer End Interrupt: When the DTC is activated with a DMAC transfer end
interrupt, the DMAC's DTE bit is not controlled by the DTC regardless of the transfer counter and
DISEL bit, and write data takes precedence.
DTCE Bit Setting: For DTCE bit setting, use bit manipulation instructions such as BSET and
BCLR. If all interrupts are masked, multiple activation sources can be set at one time by writing
data after executing a dummy read on the relevant register.
325
Advertisement
