h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 157

• Manufacturer Part Number: h8s-2172
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family H8s-2100 Series
• Manufacturer: Renesas Electronics Corporation.

6.6.6
The column address output cycle can be changed from 2 states to 3 states by setting the CAST bit
to 1 in DRAMCR. Use the setting that gives the optimum specification values (CAS pulse width,
etc.) according to the DRAM connected and the operating frequency of this LSI. Figure 6.23
shows an example of the timing when a 3-state column address output cycle is selected.
Read
Write
Figure 6.23 Example of Access Timing with 3-State Column Address Output Cycle
Column Address Output Cycle Control
φ
Address bus
Data bus
Data bus
(
(
(
(
(
,
)
)
)
)
)
T
p
Row address
(RAST = 0)
High
High
T
r
T
c1
Rev. 2.00, 03/04, page 125 of 534
Column address
T
c2
T
c3