IC42S8200 Datasheet, PDF (11/76 Pages) Integrated Circuit Solution Inc – 1Meg x 8 Bits x 2 Banks (16-MBIT) SYNCHRONOUS DYNAMIC RAM

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Mode Register Set Command
(CS, RAS, CAS, WE = LOW)
The IC42S8200 product incorporates a register that defines
the device operating mode. This command functions as a
data input pin that loads this register from the pins A0 to
A11. When power is first applied, the stipulated power-on
sequence should be executed and then the IC42S8200
should be initialized by executing a mode register set
command.
Note that the mode register set command can be executed
only when both banks are in the idle state (i.e. deactivated).
Another command cannot be executed after a mode
register set command until after the passage of the period
tMCD, which is the period required for mode register set
command execution.
Active Command
(CS, RAS = LOW, CAS, WE= HIGH)
The IS42S16100 includes two banks of 4096 rows each.
This command selects one of the two banks according to
the A11 pin and activates the row selected by the pins A0
to A10.
This command corresponds to the fall of the RAS signal
from HIGH to LOW in conventional DRAMs.
Precharge Command
(CS, RAS, WE = LOW, CAS = HIGH)
This command starts precharging the bank selected by
pins A10 and A11. When A10 is HIGH, both banks are
precharged at the same time. When A10 is LOW, the bank
selected by A11 is precharged. After executing this
command, the next command for the selected bank(s) is
executed after passage of the period tRP, which is the
period required for bank precharging.
This command corresponds to the RAS signal from LOW
to HIGH in conventional DRAMs
Read Command
(CS, CAS = LOW, RAS, WE = HIGH)
This command selects the bank specified by the A11 pin
and starts a burst read operation at the start address
specified by pins A0 to A9. Data is output following CAS
latency.
The selected bank must be activated before executing this
command.
When the A10 pin is HIGH, this command functions as a
read with auto-precharge command. After the burst read
completes, the bank selected by pin A11 is precharged.
When the A10 pin is LOW, the bank selected by the A11 pin
remains in the activated state after the burst read completes.
Write Command
(CS, CAS, WE = LOW, RAS = HIGH)
When burst write mode has been selected with the mode
register set command, this command selects the bank
specified by the A11 pin and starts a burst write operation
at the start address specified by pins A0 to A9. This first
data must be input to the I/O pins in the cycle in which this
command.
The selected bank must be activated before executing this
command.
When A10 pin is HIGH, this command functions as a write
with auto-precharge command. After the burst write
completes, the bank selected by pin A11 is precharged.
When the A10 pin is low, the bank selected by the A11 pin
remains in the activated state after the burst write completes.
After the input of the last burst write data, the application
must wait for the write recovery period (tDPL, tDAL) to elapse
according to CAS latency.
Auto-Refresh Command
(CS, RAS, CAS = LOW, WE, CKE = HIGH)
This command executes the auto-refresh operation. The
row address and bank to be refreshed are automatically
generated during this operation.
Both banks must be placed in the idle state before executing
this command.
The stipulated period (tRC) is required for a single refresh
operation, and no other commands can be executed
during this period.
The device goes to the idle state after the internal refresh
operation completes.
This command must be executed at least 4096 times every
128 ms.
This command corresponds to CBR auto-refresh in
conventional DRAMs.
Integrated Circuit Solution Inc.
11
DR018-0A 07/10/2001