HD6412373R RENESAS [Renesas Technology Corp], HD6412373R Datasheet - Page 280

• 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)
In some DRAMs provided with a self-refresh mode, the RAS signal precharge time immediately
after self-refreshing is longer than the normal precharge time. A setting can be made in bits
TPCS2 to TPCS0 in REFCR to make the precharge time immediately after self-refreshing from 1
to 7 states longer than the normal precharge time. In this case, too, normal precharging is
performed according to the setting of bits TPC1 and TPC0 in DRACCR, and therefore a setting
should be made to give the optimum post-self-refresh precharge time, including this time. Figure
6.40 shows an example of the timing when the precharge time immediately after self-refreshing is
extended by 2 states.
Rev.7.00 Mar. 18, 2009 page 212 of 1136
REJ09B0109-0700
φ
CSn (RASn)
UCAS, LCAS
HWR (WE)
Note: n = 2 to 5
T
Rp
Figure 6.39 Self-Refresh Timing
T
Rr
High
Software
standby
T
Rc3