HB52R329E22-F Datasheet, PDF (26/66 Pages) Elpida Memory – 256 MB Registered SDRAM DIMM 32-Mword × 72-bit, 100 MHz Memory Bus, 2-Bank Module (36 pcs of 16 M × 4 Components) PC100 SDRAM

HB52R329E22-F
ACTIVE clock suspend: This suspend mode ignores inputs after the next clock by internally maintaining the
bank active status.
READ suspend and READ with Auto-precharge suspend: The data being output is held (and continues to
be output).
WRITE suspend and WRIT with Auto-precharge suspend: In this mode, external signals are not accepted.
However, the internal state is held.
Clock suspend: During clock suspend mode, keep the CKE to Low.
Clock suspend mode exit: The SDRAM module exits from clock suspend mode by setting CKE to High
during the clock suspend state.
IDLE: In this state, all banks are not selected, and completed precharge operation.
Auto-refresh command [REF]: When this command is input from the IDLE state, the SDRAM module starts
auto-refresh operation. (The auto-refresh is the same as the CBR refresh of conventional DRAMs.) During the
auto-refresh operation, refresh address and bank select address are generated inside the SDRAM module. For
every auto-refresh cycle, the internal address counter is updated. Accordingly, 4096 times are required to
refresh the entire memory. Before executing the auto-refresh command, all the banks must be in the IDLE state.
In addition, since the precharge for all banks is automatically performed after auto-refresh, no precharge
command is required after auto-refresh.
Self-refresh entry [SELF]: When this command is input during the IDLE state, the SDRAM module starts
self-refresh operation. After the execution of this command, self-refresh continues while CKE is Low. Since
self-refresh is performed internally and automatically, external refresh operations are unnecessary.
Power down mode entry: When this command is executed during the IDLE state, the SDRAM module enters
power down mode. In power down mode, power consumption is suppressed by cutting off the initial input
circuit.
Self-refresh exit: When this command is executed during self-refresh mode, the SDRAM module can exit
from self-refresh mode. After exiting from self-refresh mode, the SDRAM module enters the IDLE state.
Power down exit: When this command is executed at the power down mode, the SDRAM module can exit
from power down mode. After exiting from power down mode, the SDRAM module enters the IDLE state.
Data Sheet No. E0112H10
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