
R01UH0218EJ0110 Rev.1.10
Page 196 of 664
Sep 12, 2011
R32C/142 Group and R32C/145 Group
13. DMAC II
13.5
Chained Transfer
The chained transfer is available when the CHAIN bit in the MOD is set to 1.
The chained transfer is performed as follows:
(1) When a transfer request is generated, a data transfer is performed according to the DMAC II
index specified by the corresponding interrupt vector. Either a single transfer (the BRST bit in the
MOD is 0) or burst transfer (the BRST bit is 1) is performed according to the BRST bit setting.
(2) When COUNT reaches 0000h, the value in the interrupt vector in (1) above is overwritten with
the value in CADR. Simultaneously, the DMA II transfer complete interrupt is generated when
the INTE bit in the MOD is 1.
(3) When the next DMA II transfer request is generated, the data transfer is performed according to
the DMAC II index specified by the peripheral interrupt vector in (2) above.
Figure 13.4 shows the relocatable vector and DMAC II index in a chained transfer.
To use the chained transfer, the relocatable vector table should be allocated on the RAM.
Figure 13.4 Relocatable Vector and DMAC II Index in a Chained Transfer
13.6
DMA II Transfer Complete Interrupt
The DMA II transfer complete interrupt is available when the INTE bit in the MOD is set to 1.
The start address of the DMA II transfer complete interrupt handler should be set to IADR. The interrupt
is generated when COUNT reaches 0000h.
The initial instruction of the interrupt handler is executed in the eighth cycle after a DMA II transfer is
completed.
BASE(a)
DMAC II
index (b)
INTB
DMAC II
index (a)
(CADR)
BASE(b)
(CADR)
Relocatable
vector
RAM
Peripheral interrupt vector triggering DMAC II
Default value of DMAC II: BASE(a)
BASE(b)
BASE(c)
The above vector is overwritten with BASE(b)
when a data transfer is completed
The next data transfer is performed according to
DMAC II index with the start address at BASE(b)
when a new transfer request is generated
The above vector is overwritten with BASE(c)
when the data transfer above is completed