189
7.6
DMAC Single Address Mode and DRAM Interface
When burst mode is set for the DRAM interface, the DDS bit selects the output timing for the
DACK
signal. It also selects whether or not to perform burst access when accessing the DRAM
space in DMAC single address mode.
7.6.1
DDS=1
Burst access is performed on the basis of the address only, regardless of the bus master. The
DACK
output level changes to Low afer the T
c1
state in the case of the DRAM interface.
Figure 7-30 shows the
DACK
output timing for the DRAM interface when DDS=1.
T
p
ø
Read
Write
D15 to D0
D15 to D0
A23 to A0
T
r
T
c1
T
c2
row
column
CSn (RAS)
CAS (UCAS)
LCAS (LCAS)
CAS (UCAS)
LCAS (LCAS)
DACK
HWR (WE)
HWR (WE)
RCTS= 1
RCTS= 0
Note: n = 2 to 5
Figure 7-30
DACK
Output Timing when DDS=1 (Example Showing DRAM Access)
Содержание H8S/2631
Страница 28: ...xviii Appendix G Package Dimensions 1154 ...
Страница 341: ...316 Transfer SAR or DAR DAR or SAR Block area First block Nth block Figure 9 8 Memory Mapping in Block Transfer Mode ...
Страница 918: ...905 ø DREQ0 DREQ1 tDRQS tDRQH Figure 25 19 DMAC DREQ Input Timing ...
Страница 955: ...943 A 2 Instruction Codes Table A 2 shows the instruction codes ...