IS42S16100E, IC42S16100E
Device Initialization At Power-On
Burst Length
(Power-On Sequence)
When writing or reading, data can be input or output data
continuously. In these operations, an address is input only
once and that address is taken as the starting address
internally by the device. The device then automatically
generates the following address. The burst length field in
themoderegisterstipulatesthenumberofdataitemsinput
oroutputinsequence. IntheIS42S16100E/IC42S16100E
product, a burst length of 1, 2, 4, 8, or full page can be
specified. See the table on the next page for details on
setting the mode register.
AsisthecasewithconventionalDRAMs,theIS42S16100E/
IC42S16100E product must be initialized by executing a
stipulated power-on sequence after power is applied.
After power is applied and Vdd and VddQ reach their
stipulated voltages, set and hold the CKE and DQM pins
HIGH for 100 µs. Then, execute the precharge command
to precharge both bank. Next, execute the auto-refresh
command twice or more and define the device operation
mode by executing a mode register set command.
The mode register set command can be also set before
auto-refresh command.
Burst Type
The burst data order during a read or write operation is
stipulated by the burst type, which can be set by the mode
register set command. The IS42S16100E/IC42S16100E
product supports sequential mode and interleaved mode
burst type settings. See the table on the next page for
details on setting the mode register. See the “Burst Length
and Column Address Sequence” item for details on DQ
data orders in these modes.
Mode Register Settings
The mode register set command sets the mode register.
When this command is executed, pins A0 to A9, A10, and
A11 function as data input pins for setting the register, and
this data becomes the device internal OP code. This OP
code has four fields as listed in the table below.
Input Pin
A11, A10, A9, A8, A7
A6, A5, A4
Field
Write Mode
Burst write or single write mode is selected by the OPcode
(A11, A10, A9) of the mode register.
Mode Options
CAS Latency
Burst Type
A3
A burst write operation is enabled by setting the OP code
(A11, A10, A9) to (0,0,0). A burst write starts on the same
cycle as a write command set. The write start address is
specified by the column address and bank select address
at the write command set cycle.
A2, A1, A0
Burst Length
Notethatthemoderegistersetcommandcanbeexecuted
only when both banks are in the idle (inactive) state. Wait
at least two cycles after executing a mode register set
command before executing the next command.
AsinglewriteoperationisenabledbysettingOPcode(A11,
A10,A9) to (0, 0,1). In a single write operation, data is only
written to the column address and bank select address
specified by the write command set cycle without regard
to the bust length setting.
CAS Latency
During a read operation, the between the execution of the
read command and data output is stipulated as the CAS
latency. This period can be set using the mode register
set command. The optimal CAS latency is determined
by the clock frequency and device speed grade. See the
“Operating Frequency / Latency Relationships” item for
details on the relationship between the clock frequency
and the CAS latency. See the table on the next page for
details on setting the mode register.
Integrated Silicon Solution, Inc. — www.issi.com
21
Rev. C
01/22/08
ISSI [ INTEGRATED SILICON SOLUTION, INC ]
