HD6432670 Hitachi, HD6432670 Datasheet - Page 228

• Manufacturer Part Number: HD6432670
• Description: (HD64F267x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

6.6.10
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 6.28 shows the control timing for 2-CAS access, and
figure 6.29 shows an example of 2-CAS DRAM connection.
Rev. 2.0, 04/02, page 182 of 906
Note: n = 2 to 5
ø
Address bus
Upper data bus
Lower data bus
Byte Access Control
(
(
(
)
)
)
(Upper Byte Write Access: RAST = 0, CAST = 0)
Figure 6.28 2-CAS Control Timing
T
p
Row address
High
High
T
r
T
c1
Column address
Write data
High-Z
T
c2