Datasheet

Section 6 Bus Controller (BSC)
Rev. 3.00 Mar 17, 2006 page 192 of 926
REJ09B0283-0300
T
Rp
φ
CSn (RASn)
T
Rrw
T
Rr
T
Rc1
UCAS, LCAS
T
Rc2
Figure 6.37 CBR Refresh Timing
(RCW1 = 0, RCW0 = 1, RLW1 = 0, RLW0 = 0)
Depending on the DRAM used, modification of the WE signal may not be permitted during the
refresh period. In this case, the CBRM bit in REFCR should be set to 1. The bus controller will
then insert refresh cycles in appropriate breaks between bus cycles. Figure 6.38 shows an example
of the timing when the CBRM bit is set to 1. In this case the CS signal is not controlled, and
retains its value prior to the start of the refresh period.