Section 12 Bus State Controller (BSC)
Table 12.19 Minimum Number of Idle Cycles between Access Cycles during DMAC Dual
Address Mode Transfer for the Normal Space Interface
BSC Register Setting
CSnWCR.
CSnBCR
WM Setting
Idle Setting
1
0
0
0
1
1
0
1
1
2
0
2
1
4
0
4
0, 1
n (n≥6)
Notes:
DMAC is operated by Bφ. The minimum number of idle cycles is not affected by
changing a clock ratio.
1. Minimum number of idle cycles between the upper and lower 16-bit access cycles in the
32-bit access cycle when the bus width is 16 bits, and the minimum number of idle
cycles between continuous access cycles during 16-byte transfer
2. Minimum number of idle cycles for other than the above cases.
Rev. 4.00 Sep. 14, 2005 Page 390 of 982
REJ09B0023-0400
When Access Size is
Less than Bus Width
Read to
Write to
Write
Read
2
0
2
1
2
1
2
1
2
2
2
2
4
4
4
4
n
n
When Access Size Exceeds Bus Width
Continuous
Read to
1
2
Read*
Write*
0
2
1
2
1
2
1
2
2
2
2
2
4
4
4
4
n
n
Continuous
Write to
1
2
Write*
Read*
0
0
1
1
1
1
1
1
2
2
2
2
4
4
4
4
n
n