HD6412373R RENESAS [Renesas Technology Corp], HD6412373R Datasheet - Page 290

• Manufacturer Part Number: HD6412373R
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 6 Bus Controller (BSC)
6.7.7
CAS latency is controlled by settings of the W22 to W20 bits of WTCRB. Set the CAS latency
count, as shown in table 6.10, by the setting of synchronous DRAM. Depending on the setting, the
CAS latency control cycle (T
AST2 bit of ASTCR. Figure 6.45 shows the CAS latency control timing when synchronous
DRAM of CAS latency 3 is connected.
The initial value of W22 to W20 is H'7. Set the register according to the CAS latency of
synchronous DRAM to be connected.
Table 6.10 Setting CAS Latency
W22
0
1
Rev.7.00 Mar. 18, 2009 page 222 of 1136
REJ09B0109-0700
CAS Latency Control
W21
0
1
0
1
W20
0
1
0
1
0
1
0
1
c1
Description
Connect synchronous DRAM of CAS
latency 1
Connect synchronous DRAM of CAS
latency 2
Connect synchronous DRAM of CAS
latency 3
Connect synchronous DRAM of CAS
latency 4
Reserved (must not used)
Reserved (must not used)
Reserved (must not used)
Reserved (must not used)
) is inserted. WTCRB can be set regardless of the setting of the
CAS Latency Control
Cycle Inserted
0 state
1 state
2 states
3 states
⎯
⎯
⎯
⎯