RL78/G13 CHAPTER 15 DMA CONTROLLER
R01UH0146EJ0100 Rev.1.00 821
Sep 22, 2011
(4) DMA pending instruction
Even if a DMA request is generated, DMA transfer is held pending immediately after the following instructions.
• CALL !addr16
• CALL $!addr20
• CALL !!addr20
• CALL rp
• CALLT [addr5]
• BRK
• Bit manipulation instructions for registers IF0L, IF0H, IF1L, IF1H, IF2L, IF2H, IF3L, MK0L, MK0H, MK1L, MK1H,
MK2L, MK2H, MK3L, PR00L, PR00H, PR01L, PR01H, PR02L, PR02H, PR03L, PR10L, PR10H, PR11L,
PR11H, PR12L, PR12H, PR13L, and PSW each.
• Instruction for accessing the data flash memory
(5) Operation if address in general-purpose register area or other than those of internal RAM area is specified
The address indicated by DMA RAM address register n (DRAn) is incremented during DMA transfer. If the
address is incremented to an address in the general-purpose register area or exceeds the area of the internal
RAM, the following operation is performed.
z In mode of transfer from SFR to RAM
The data of that address is lost.
z In mode of transfer from RAM to SFR
Undefined data is transferred to SFR.
In either case, malfunctioning may occur or damage may be done to the system. Therefore, make sure that the
address is within the internal RAM area other than the general-purpose register area.
Internal RAM
General-purpose registers
DMA transfer enabled area
FFF00H
FFEFFH
FFEE0H
FFEDFH
(6) Operation if instructions for accessing the data flash area
• Because DMA transfer is suspended to access to the data flash area, be sure to add the DMA pending
instruction.
If the data flash area is accessed after an next instruction execution from start of DMA transfer, a 3-clock wait
will be inserted to the next instruction.
Instruction 1
DMA transfer
Instruction 2 The wait of three clock cycles occurs.
MOV A, ! DataFlash area
<R>
<R>
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