Mitsubishi microcomputers
M16C / 61 Group
DMAC
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(1) 8-bit transfers
16-bit transfers from even address and the source address is even.
BCLK
Address
bus
Dummy
cycle
CPU use
Source
Destination
CPU use
RD signal
WR signal
Data
bus
Dummy
cycle
CPU use
Source
Destination
CPU use
(2) 16-bit transfers and the source address is odd
Transferring 16-bit data on an 8-bit data bus (In this case, there are also two destination write cycles).
BCLK
Address
bus
Dummy
cycle
CPU use
Source
Source + 1 Destination
CPU use
RD signal
WR signal
Data
bus
Dummy
cycle
CPU use
Source + 1
Source
CPU use
Destination
(3) One wait is inserted into the source read under the conditions in (1)
BCLK
Address
bus
Dummy
cycle
CPU use
Source
Destination
CPU use
RD signal
WR signal
Data
bus
Dummy
cycle
CPU use
Source
Destination
CPU use
(4) One wait is inserted into the source read under the conditions in (2)
(When 16-bit data is transferred on an 8-bit data bus, there are two destination write cycles).
BCLK
Address
bus
Dummy
cycle
CPU use
Source
Source + 1
Destination
CPU use
RD signal
WR signal
Data
bus
Dummy
cycle
CPU use
Source
Source + 1
Destination
CPU use
Note: The same timing changes occur with the respective conditions at the destination as at the source.
Figure 1.15.4. Example of the transfer cycles for a source read
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MITSUBISHI [ Mitsubishi Group ]
