Toshiba H1 Series - Manual (Page 233)

TMP92CZ26A
92CZ26A-230
(c) Full-page read, the read data shift function enabled (SDACR<SRDS> = “1”,
<SRDSCK> = “0”)
(5) Read/Write commands
The Read/Write commands to be used in 1-word read/single write mode can be specified by
using SDACR<SPRE>.
When SDACR<SPRE> is set to “1”, the Read/Write commands are executed with Auto
Precharge. When Auto Precharge is enabled, the SDRAM is automatically precharged
internally at every access cycle. Thus, the SDRAM is always in a “bank idle” state while it is
not being accessed. This helps reduce the power consumption of the SDRAM but at the cost of
degradation in performance as the Bank Active command is needed at every access cycle.
When SDACR<SPRE> is set to “0”, the Read/Write commands are executed without Auto
Precharge. In this case, the SDRAM is not precharged at every access cycle and is always in a
“bank active” state. This increases the power consumption of the SDRAM, but improves
performance as there is no need to issue the Bank Active command at every access cycle. If an
access is made to outside the SDRAM page boundaries or if the Auto Refresh command is
issued, the SDRAMC automatically issues the Precharge All command.
SDCLK
COMMAND ACTIVE NOP NOP READ NOP
D15-D0 DIN1
A15-A0 Row Address
NOP
Internal system
clock
Internal data bus DIN1
External data latch CPU data read
DIN2
DIN2
DIN3
DIN3
NOP
ColumnAddress