Hitachi SH7032 Hardware Manual page 186

Short-Pitch, High-Speed Page Mode and Long-Pitch High-Speed Page Mode: When burst
operation is selected by setting the BE bit to 1 in DCR, short pitch high-speed page mode or long
pitch high-speed page mode can be selected by setting the RW1, WW1, DRW1, and DWW1 bits
in WCR1 and WCR2.
• Short-pitch, high-speed page mode: When the RW1, WW1, DRW1, and DWW1 bits in WCR1
and WCR2 are cleared to 0, and the corresponding DRAM access cycle is continuing, the CAS
signal and column address output cycles continue as long as the row addresses continue to
match. The column address output cycle is performed in 1 state and the WAIT signal is not
sampled. Figure 8.23 shows the read cycle timing for short-pitch, high-speed page mode.
T p
CK
A21–
A0
RAS
CAS
WR
AD15–
A0
Figure 8.23 Short-Pitch, High-Speed Page Mode (Read Cycle)
When the write cycle continues for the same row address in short-pitch, high-speed page
mode, an open cycle (silent cycle) is produced for 1 cycle only. This timing is shown in figure
8.24. Likewise, when a write cycle continues after the read cycle for the same row address, a
silent cycle is produced for 1 cycle. This timing is shown in figure 8.25. Note also that when
DRAM is written to in short-pitch, high-speed page mode when using DMAC single address
mode, a silent cycle is inserted in each transfer. The details of timing are discussed in sections
20.1.3 (3) and 20.2.3 (3), Bus Timing.
T r T c
Column
address 1
Row address 1
T c T c
Column Column
address 2 address 3
Data 1 Data 2
T c
Column
address 4
Data 3 Data 4
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