198
Chapter 7
DMA Functions (DMA Controller)
Preliminary User’s Manual U15839EE1V0UM00
7.13 Precautions
(1)
Memory boundary
The transfer operation is not guaranteed if the source or the destination address exceeds the area
of DMA objects (internal RAM, or peripheral I/O) during DMA transfer.
(2)
Transfer of misaligned data
DMA transfer of 16-bit/32-bit bus width misaligned data is not supported.
(3)
Times related to DMA transfer
The overhead before and after DMA transfer and the minimum execution clock for DMA transfer
are shown below.
• Internal RAM access: 2 clocks
(4)
Bus arbitration for CPU
The CPU can access on-chip peripheral I/O, and internal RAM not undergoing DMA transfer.
While data transfer is being executed between internal RAMs, the CPU can access external mem-
ory and peripheral I/O.
(5)
Interrupt factors
DMA transfer is interrupted if a bus hold is issued.
If the factor (bus hold) interrupting DMA transfer disappears, DMA transfer promptly restarts.
Summary of Contents for mPD703128
Page 6: ...6 Preliminary User s Manual U15839EE1V0UM00 ...
Page 20: ...20 Preliminary User s Manual U15839EE1V0UM00 ...
Page 32: ...32 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 154: ...154 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 238: ...238 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 356: ...356 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 522: ...522 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 600: ...600 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 610: ...610 Preliminary User s Manual U15839EE1V0UM00 ...
Page 612: ......