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DMAC
9.1 Summary of DMAC
9.1 Summary of DMAC
The M32150F4TFP is provided with 5 channels of the DMAC (Direct Memory Access Controller), which
performs high-speed data transfer between internal peripheral I/Os, between internal RAM and internal
peripheral I/O, and between internal RAMs by software triggering or request from internal peripheral I/Os.
Table 9.1.1 Summary of DMAC
Item
Description
Number of Channels
5 channels
Transfer requests
• Software trigger
• Request from internal peripheral I/Os: A-D converter, multi-junction
timers, and serial I/O (channels 0 and 1: receive complete,
channel 0: transmit buffer empty)
• DMA channels can be connected in cascade (see note 1)
Number of maximum transfers
256 times
Address space available
• 64K bytes (address space of H'0080 0000 to H'0080 FFFF)
in transfer
(see note 2)
• Supports transfer between internal peripheral I/Os, between internal
RAM and internal peripheral I/O, and between internal RAMs
Transfer data size
16 bits or 8 bits
Transfer method
Single transfer DMA (internal bus is relinquished at each DMA transfer)
Dual address transfer
Transfer direction mode
Fixed address or incremented address is selectable for source and
destination addresses.
Channel priority
Channel 0 > channel 1 > channel 2 > channel 3 > channel 4
(fixed priority)
Maximum transfer rate
16.6 M bytes/s (at 25 MHz internal operation)
Interrupt request
An interrupt request can be generated at the underflow of each transfer
count register.
Others
The ring buffer mode available
Notes 1: DMA
The
The
The
The
channels can be
DMA transfer of
DMA transfer of
DMA transfer of
DMA transfer of
connected
channel 1
channel 2
channel 0
channel 4
in cascade in the following way:
is started upon end of the DMA
is started upon end of the DMA
is started upon end of the DMA
is started upon end of the DMA
transfer
transfer
transfer
transfer
of
of
of
of
channel
channel
channel
channel
0.
1.
2.
3.
2: The addresses following the beginning 16K bytes in the internal RAM/SFR area (H'0080 4000 to
H'0080 FFFF) are ghosts (not to be designated as transfer addresses of DMAC).
9-2
M32150F4TFP User's Manual