r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 260

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

Section 6 Bus Controller (BSC)
6.7.10
When DRAM with a ×16-bit configuration is connected, the 2-CAS access method is used for the
control signals needed for byte access. Figure 6.40 shows the control timing for 2-CAS access,
and figure 6.41 shows an example of 2-CAS DRAM connection.
Rev. 1.00 Sep. 19, 2008 Page 230 of 1342
REJ09B0467-0100
Note: n = 2 to 5
φ
Address bus
RASn (CSn)
UCAS
LCAS
WE (HWR)
OE (RD)
Upper data bus
Lower data bus
Byte Access Control
(Upper Byte Write Access: RAST = 0, CAST = 0)
Figure 6.40 2-CAS Control Timing
T
p
Row address
High
High
T
r
T
c1
Column address
Write data
High-Z
T
c2