r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 267

• Manufacturer Part Number: r4f2456
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

A setting can be made in bits RCW1 and RCW0 in REFCR to delay RAS signal output by one to
three cycles. Use bits RLW1 and RLW0 in REFCR to adjust the width of the RAS signal. The
settings of bits RCW1, RCW0, RLW1, and RLW0 are valid only in refresh operations.
Figure 6.49 shows the timing when bits RCW1 and RCW0 are set.
φ
RTCNT
RTCOR
Refresh request
signal and CMF bit
setting signal
φ
CSn (RASn)
UCAS, LCAS
Figure 6.47 Compare Match Timing
Figure 6.48 CBR Refresh Timing
T
Rp
N
T
Rr
N
T
Rev. 1.00 Sep. 19, 2008 Page 237 of 1342
Rc1
Section 6 Bus Controller (BSC)
H'00
T
Rc2
REJ09B0467-0100