SH7147 Datasheet, PDF (221/1108 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH™ RISC engine Family

Section 8 Data Transfer Controller (DTC)
8.9.7 Notes on IRQ Interrupt as DTC Activation Source
• The IRQ interrupt specified as a DTC activation source must not be used to cancel software
standby mode.
• The IRQ edge input in software standby mode must not be specified as a DTC activation
source.
• When a low level on the IRQ pin is to be detected, if the end of DTC transfer is used to request
an interrupt to the CPU (transfer counter = 0 or DISEL = 1), the IRQ signal must be held low
until the CPU accepts the interrupt.
8.9.8 Note on SCI as DTC Activation Sources
• When the TXI interrupt from the SCI is specified as a DTC activation source, the TEND flag
in the SCI must not be used as the transfer end flag.
8.9.9 Clearing Interrupt Source Flag
The interrupt source flag set when the DTC transfer is completed should be cleared in the interrupt
handler in the same way as for general interrupt source flags. For details, refer to section 6.9,
Usage Note.
8.9.10 Conflict between NMI Interrupt and DTC Activation
When a conflict occurs between the generation of the NMI interrupt and the DTC activation, the
NMI interrupt has priority. Thus the ERR bit is set to 1 and the DTC is not activated.
It takes 1 × Bcyc + 3 × Pcyc for checking DTC stop by the NMI, 2 × Bcyc for checking DTC
activation by the IRQ, and 1 × Pcyc for checking DTC activation by the peripheral module.
Rev. 3.00 Oct. 06, 2008 Page 197 of 1080
REJ09B0230-0300