
R8C/3GM Group
15. DTC
R01UH0284EJ0100 Rev.1.00
Aug 09, 2011
Figure 15.3
DTC Internal Operation Flowchart When DTC Activation Source is not SSU/I2C bus,
Timer RC, or Flash Memory Interrupt Source
Figure 15.4
DTC Internal Operation Flowchart When DTC Activation Source is Timer RC Interrupt
Source
DTC activation source
generation
NMIF = 1?
Read DTC vector
Read control data
Transfer data
Write back control data
CHNE=1?
Branch 1
0 is written to the bit among bits DTCENi0 to DTCENi7 and an interrupt request is generated
when transfer is either of the following:
- Transfer causing the DTCCTj (j = 0 to 23) register value to change from 1 to 0 in normal mode
- Transfer causing the DTCCTj register value to change from 1 to 0 while the RPTINT bit is 1 in
repeat mode
Yes
No
DTCENi0 to DTCENi7: Bits in DTCENi (i = 0 to 3, 5 to 6) registers
RPTINT, CHNE: Bits in DTCCRj registers
NMIF: Bit in DTCTL register
Branch 1
End
No
Yes
Read control data
Transfer data
Write back control data
CHNE=1?
No
Write 0 to the bit among
DTCENi0 to DTCENi7
Generate an interrupt request
for the CPU
Transfer data
Write back control data
CHNE=1?
Yes
No
Interrupt handling
Read control data
Transfer data
Write back control data
CHNE=1?
Yes
No
DTC activation source
generation
NMIF = 1?
Read DTC vector
Read control data
Write 0 to the interrupt source
flag in the status register
Transfer data
Branch 1
0 is written to the bit among bits DTCENi0 to DTCENi7 and an interrupt request is generated
when transfer is either of the following:
- Transfer causing the DTCCTj (j = 0 to 23) register value to change from 1 to 0 in normal mode
- Transfer causing the DTCCTj register value to change from 1 to 0 while the RPTINT bit is 1 in
repeat mode
Yes
DTCENi0 to DTCENi7: Bits in DTCENi (i = 0 to 3, 5 to 6) registers
RPTINT, CHNE: Bits in DTCCRj registers
NMIF: Bit in DTCTL register
Branch 1
No
Yes
Read control data
Transfer data
Write back control data
CHNE=1?
No
Write 0 to the bit among
DTCENi0 to DTCENi7
Generate an interrupt request
for the CPU
Transfer data
Write back control data
CHNE=1?
Yes
No
Interrupt handling
Read control data
Transfer data
Write back control data
CHNE=1?
Yes
No
CHNE=1?
No
End
Yes
Write back control data