IS42S16400F-7TLI INTEGRATED SILICON SOLUTION (ISSI), IS42S16400F-7TLI Datasheet - Page 17

• Manufacturer Part Number: IS42S16400F-7TLI
• Description: SDRAM, IND, 4M X 16, 3V, 54TSOP2
• Manufacturer: INTEGRATED SILICON SOLUTION (ISSI)

Specifications of IS42S16400F-7TLI

• Access Time: 5.4ns
• Page Size: 64Mbit
• Memory Case Style: TSOP-2
• No. Of Pins: 54
• Operating Temperature Range: -40°C To +85°C
• Memory Type: DRAM - Synchronous
• Memory Configuration: 4 BLK (1M X 16)
• Interface Type: LVTTL
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

IS42S16400F
IS45S16400F
FUNCTIONAL DESCRIPTION
The 64Mb SDRAMs (1 Meg x 16 x 4 banks) are quad-bank
DRAMs which operate at 3.3V and include a synchronous
interface (all signals are registered on the positive edge of
the clock signal, CLK). Each of the 16,777,216-bit banks is
organized as 4,096 rows by 256 columns by 16 bits.
Read and write accesses to the SDRAM are burst oriented;
accesses start at a selected location and continue for
a programmed number of locations in a programmed
sequence. Accesses begin with the registration of an AC-
TIVE command which is then followed by a READ orWRITE
command.The address bits registered coincident with the
ACTIVE command are used to select the bank and row to
be accessed (BA0 and BA1 select the bank, A0-A11 select the
row).The address bits (A0-A7) registered coincident with the
READ or WRITE command are used to select the starting
column location for the burst access.
Prior to normal operation, the SDRAM must be initial-
ized. The following sections provide detailed information
covering device initialization, register definition, command
descriptions and device operation.
Integrated Silicon Solution, Inc. — www.issi.com
Rev. H
07/28/2010
Initialization
SDRAMs must be powered up and initialized in a
predefined manner.
The 64Mb SDRAM is initialized after the power is applied
to V
with DQM High and CKE High.
A 100µs delay is required prior to issuing any command
other than a COMMAND INHIBIT or a NOP.The COMMAND
INHIBIT or NOP may be applied during the 100µs period and
continue should at least through the end of the period.
With at least one COMMAND INHIBIT or NOP command
having been applied, a PRECHARGE command should
be applied once the 100µs delay has been satisfied. All
banks must be precharged. This will leave all banks in
an idle state, after which at least two AUTO REFRESH cycles
must be performed. After the AUTO REFRESH cycles are
complete, the SDRAM is then ready for mode register
programming.
The mode register should be loaded prior to applying
any operational command because it will power up in an
unknown state. After the Load Mode Register command,
at least one NOP command must be asserted prior to
any command.
dd
and V
ddq
(simultaneously), and the clock is stable
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