HD6417034B RENESAS [Renesas Technology Corp], HD6417034B Datasheet - Page 203

• Manufacturer Part Number: HD6417034B
• Description: 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

2. Bus release procedure
c. Refresh cycle + bus cycle
The bus release procedure is shown in figure 8.47. Figure 8.47 shows the case where BREQ is
input one state before the break between bus cycles so that tBRQS is satisfied. In the SH7032
and SH7034, the bus is released after the bus cycle in which BREQ is input (if BREQ is input
between bus cycles, after the bus cycle starting next).
The bus is never released during a refresh cycle and the following bus cycle ((a) or (b)
above)) (figure 8.46).
RAS, CAS
A21 to A0
RD, WR
BREQ
BACK
CSn
CK
Figure 8.46 Refresh Cycle and Following Bus Cycle
t
BRQS
Bus cycle
The bus is released after the bus
cycle in which BREQ is input
(if BREQ is input between bus cycles,
after the bus cycle starting next).
Figure 8.47 Bus Release Procedure
Refresh cycle
Cycle during which bus
is not released
high-level output
Strobe pin:
t
t
BZD
BZD
1 bus cycle
t
BACD1
Rev. 7.00 Jan 31, 2006 page 177 of 658
high impedance
Address & data
strobe pins:
Section 8 Bus State Controller (BSC)
t
Bus release
BRQS
t
BACD2
Bus cycle restart
Bus cycle
REJ09B0272-0700