M16C30L Datasheet, PDF (74/166 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

DMAC
Mitsubishi microcomputers
M16C / 30L Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(2) DMAC transfer cycles
Any combination of even or odd transfer read and write addresses is possible. Table 1.13.2 shows the
number of DMAC transfer cycles.
The number of DMAC transfer cycles can be calculated as follows:
No. of transfer cycles per transfer unit = No. of read cycles x j + No. of write cycles x k
Table 1.13.2. No. of DMAC transfer cycles
Transfer unit
8-bit transfers
(DMBIT= “1”)
16-bit transfers
(DMBIT= “0”)
Bus width
16-bit
(BYTE= “L”)
8-bit
(BYTE = “H”)
16-bit
(BYTE = “L”)
8-bit
(BYTE = “H”)
Access address
Even
Odd
Even
Odd
Even
Odd
Even
Odd
Single-chip mode Memory expansion mode
Microprocessor mode
No. of read No. of write No. of read No. of write
cycles
cycles
cycles
cycles
1
1
1
1
1
1
1
1
—
—
1
1
—
—
1
1
1
1
1
1
2
2
2
2
—
—
2
2
—
—
2
2
Coefficient j, k
Internal memory
Internal ROM/RAM Internal ROM/RAM
No wait
With wait
1
2
SFR area
2
External memory
Separate bus Separate bus
No wait
With wait
1
2
Multiplex
bus
3
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