HD6432670 Hitachi, HD6432670 Datasheet - Page 237

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

In some DRAMs provided with a self-refresh mode, the 5$6 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.
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Note: n = 2 to 5
(
(
,
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)
T
Rp
Figure 6.39 Self-Refresh Timing
T
Rr
High
Software
standby
Rev. 2.0, 04/02, page 191 of 906
T
Rc3