Epson S1C33210 Technical Manual page 257

High-speed DMA
The underflow interrupt factor of the timer 0 to 3 can also invoke high-speed DMA (HSDMA).
The following shows the HSDMA channel number and trigger set-up bit corresponding to the timer 0 to 3:
Timer HSDMA channel
Timer 0
Timer 1
Timer 2
Timer 3
For HSDMA to be invoked, the trigger set-up bits should be set to "0101" in advance. Transfer conditions, etc.
must also be set on the HSDMA side.
If the 8-bit timer is selected as the HSDMA trigger, the HSDMA channel is invoked through generation of the
interrupt factor.
For details on HSDMA transfer, refer to "HSDMA (High-Speed DMA)".
Trap vectors
The trap vector addresses for individual underflow interrupt factors are set by default as shown below:
Timer 0 underflow interrupt: 0x0C000D0
Timer 1 underflow interrupt: 0x0C000D4
Timer 2 underflow interrupt: 0x0C000D8
Timer 3 underflow interrupt: 0x0C000DC
The base address of the trap table can be changed using the TTBR register (0x48134 to 0x48137).
S1C33210 FUNCTION PART
Table 3.5 HSDMA Trigger Set-up Bits
0 HSD0S[3:0] (D[3:0]) / HSDMA Ch.0/1 trigger set-up register (0x40298)
1 HSD1S[3:0] (D[7:4]) / HSDMA Ch.0/1 trigger set-up register (0x40298)
2 HSD2S[3:0] (D[3:0]) / HSDMA Ch.2/3 trigger set-up register (0x40299)
3 HSD3S[3:0] (D[7:4]) / HSDMA Ch.2/3 trigger set-up register (0x40299)
III PERIPHERAL BLOCK: 8-BIT PROGRAMMABLE TIMERS
Trigger set-up bits
EPSON
B-III-3-9