W989D6DB Datasheet, PDF (16/64 Pages) Winbond – Standard Self Refresh Mode

W989D6DB / W989D2DB
7.1.11 Extended Mode Register Set Command
( RAS = L, CAS = L, WE = L, BA1, A0~An = Register Data)
The Extended Mode Register Set command is designed to support Partial Array Self Refresh, Temperature
Compensated Self Refresh, and Output Driver Strength/Size by allowing users to program each value by setting
predefined address bits. The default values in the Extended Mode Register after power-up are undefined;
therefore this command must be issued during the power-up sequence. Also, this command can be issued while
all banks are in the idle state.
7.1.12 Mode Register Set Command
( RAS = L, CAS = L, WE = L, BA1, A0~An = Register Data)
The Mode Register Set command is used to program the values of CAS latency, Addressing Mode and Burst
Length in the Mode Register. The default values in the Mode Register after power-up are undefined; therefore this
command must be issued during the power-up sequence and re-issued after the Deep Power Down Exit
Command. Also, this command can be issued while all banks are in the idle state.
7.1.13 No-Operation Command
( RAS = H, CAS = H, WE = H)
The No-Operation command is used in cases such as preventing the device from registering unintended
commands. The device performs no operation when this command is registered. This command is functionally
equivalent to the Device Deselect command.
7.1.14 Burst Stop Command
( RAS = H, CAS = H, WE = L)
The Burst stop command is used to stop the already activated burst operation. The activated page is left unclosed
and future commands can be issued to access the same page of the active bank. If this command is issued
during a burst read operation, the read data will go to a Hi-Z state after a delay equal to the CAS latency. If a
burst stop command is issued during a burst write operation, then the burst data is terminated and data bus goes
to Hi-Z at the same clock that the burst command is activated. Any remaining data from the burst write cycle is
ignored.
7.1.15 Device Deselect Command
( CS = H)
The Device Deselect command disables the command decoder so that the RAS , CAS , WE and Address
inputs are ignored. This command is similar to the No-Operation command.
7.1.16 Auto Refresh Command
( RAS = L, CAS = L, WE = H, CKE = H, BA0, BA1, A0~An = Don’t care)
The Auto Refresh command is used to refresh the row address provided by the internal refresh counter. The
Refresh operation must be performed 8192 times within 64 mS. The next command can be issued after tRC from
the end of the Auto Refresh command. When the Auto Refresh command is issued, All banks must be in the idle
state. The Auto Refresh operation is equivalent to the CAS -before- RAS operation in a conventional DRAM.
7.1.17 Self Refresh Entry Command
( RAS = L, CAS = L, WE = H, CKE = L, BA0, BA1, A0~An = Don’t care)
When the Self Refresh Entry command is issued, the device enters the Self Refresh mode. While the device is in
Self Refresh mode, the device automatically refreshes memory cells, and all input and I/O buffers (except the
CKE buffer) are disabled. By asserting the CKE signal “high” (and by issuing the Self Refresh Exit command), the
device exits the Self Refresh mode.
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Publication Release Date: Mar. 19, 2014
Revision: A01-001