upd70f3402 Renesas Electronics Corporation., upd70f3402 Datasheet - Page 510

• Manufacturer Part Number: upd70f3402
• Description: 32-/16-bit Single-chip Microcontroller With Can Interface
• Manufacturer: Renesas Electronics Corporation.

Caution:
(5)
Caution:
Note: When the value of DMBCn register is read as 0, it can either mean that there is one remaining
510
DMBCn BC15 BC14 BC13 BC12 BC11 BC10 BC9 BC8 BC7 BC6 BC5 BC4 BC3 BC2 BC1 BC0
R/W
Internal RAM
External Memory
On-chip Peripheral I/O
The number of relevant bits of DA25 - DA0 is as follows:
DMA transfer count register (DMBCn)
The DMBCn register sets the transfer count for DMA channel n. It holds the number of remaining
transfers during a DMA transfer. The value is decremented with each transfer and hold a value of
0 at the end of a DMA transfer. The register can be read or written in 16-bit units.
DA25 - DA0
BC15 - BC0
transfer pending, or that the transfer is completed. The EN bit can be used to determine if a fur-
ther transfer is pending or if the transfer is completed.
FFFFH
R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W
0000H
0001H
15
Transfer object
...
Write to DMBCn is permitted only when EN = 0 (DMCHCn register).
SA0 and DA0 have to be set to 0, when DMA transfer size is halfword.
SA0 and DA0 and SA1 and DA1 have to be set to 0, when DMA transfer size is word.
Figure 15-6: DMA Destination Address Register (DMDAn) Format (2/2)
14
13
Figure 15-7: DMA Transfer Count Register (DMBCn) Format
1 transfer remaining
2 transfers remaining
...
65536 transfers remaining
DMBC0=FFFFFE10H, DMBC1=FFFFFE1CH, DMBC2=FFFFFE28H,
DMA transfer destination address (address signals A25 - A0).
If address increment is selected for the DMA transfer, the address will be updated after
each transfer to the next transfer address.
DMBC3=FFFFFE34H, DMBC4=FFFFFE40H, DMBC5=FFFFFE4CH
12
Chapter 15 DMA Functions (DMA Controller)
11
Set the lower 16-bit address for DA15 - DA0
Set the lower 26-bit address for DA25 - DA0
Set the lower 14-bit address for DA13 - DA0
10
User’s Manual U16702EE3V2UD00
Note
9
8
7
DMA Transfer Counter
6
Setting of DA25 - DA0
5
4
3
2
1
0
Address
undef.
reset
After