r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 274

• Manufacturer Part Number: r4f2456
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

Section 6 Bus Controller (BSC)
(2)
When DRAM space is accessed in DMAC or EXDMAC single address transfer mode, full access
(normal access) is always performed. With the DRAM interface, the DACK or EDACK output
goes low from the T
In modes other than DMAC or EXDMAC single address transfer mode, burst access can be used
when accessing DRAM space.
Figure 6.54 shows the DACK or EDACK output timing for the DRAM interface when DDS = 0 or
EDDS = 0.
Rev. 1.00 Sep. 19, 2008 Page 244 of 1342
REJ09B0467-0100
Read
Write
Note: n = 2 to 5
Figure 6.54 Example of DACK/EDACK Output Timing when DDS = 0 or EDDS = 0
When DDS = 0 or EDDS = 0
DACK or EDACK
φ
Address bus
RASn (CSn)
UCAS, LCAS
WE (HWR)
OE (RD)
Data bus
WE (HWR)
OE (RD)
Data bus
r
state.
T
p
Row address
(RAST = 0, CAST = 1)
High
High
T
r
T
c1
Column address
T
c2
T
c3