SH7720 Datasheet, PDF (446/1524 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 9 Bus State Controller (BSC)
CKIO
A25 to A0
BA1*¹
BA0*²
A12/A11*³
CSn
RAS
CAS
RD/WR
DQMxx
D31 to D0
BS
DACKn*⁴
Tp
Tpw
Trr
Trc
PALL
REF
Trc
Trr
Trc
REF
Hi-Z
Trc Tmw Tnop Temw Tnop
MRS
EMRS
Notes: 1. Address pin to be connected to the BA1 pin of SDRAM.
2. Address pin to be connected to the BA0 pin of SDRAM.
3. Address pin to be connected to the A10 pin of SDRAM.
4. The waveform for DACKn is when active low is specified.
Figure 9.29 EMRS Command Issue Timing
• Deep power-down mode
The low-power SDRAM supports the deep power-down mode as a low-power consumption
mode. In the partial self-refresh function, self-refresh is performed on a specific area. In the
deep power-down mode, self-refresh will not be performed on any memory area. This mode is
effective in systems where all of the system memory areas are used as work areas.
If the RMODE bit of the SDCR is set to 1 while the DEEP and RFSH bits of the SDCR are set to
1, the low-power SDRAM enters the deep power-down mode. If the RMODE bit is cleared to 0,
the CKE signal is pulled high to cancel the deep power-down mode. Before executing an access
after returning from the deep power-down mode, the power-up sequence must be re-executed.
Rev. 3.00 Jan. 18, 2008 Page 384 of 1458
REJ09B0033-0300