IS42S16400F
IC42S16400F
PIN FUNCTIONS
Symbol
A0-A11
TSOP Pin No.
23 to 26
29 to 34
22, 35
Type
Input Pin
Function (In Detail)
Address Inputs: A0-A11 are sampled during the ACTIVE
command (row-address A0-A11) and READ/WRITE command (A0-A7
with A10 defining auto precharge) to select one location out of the memory array
in the respective bank. A10 is sampled during a PRECHARGE command to deter-
mine if all banks are to be precharged (A10 HIGH) or bank selected by
BA0, BA1 (LOW). The address inputs also provide the op-code during a LOAD
MODE REGISTER command.
Input Pin
Input Pin
Input Pin
Bank Select Address: BA0 and BA1 defines which bank the ACTIVE, READ, WRITE
or PRECHARGE command is being applied.
CAS,
in conjunction with the
RAS
and
WE,
forms the device command. See the
"Command Truth Table" for details on device commands.
The CKE input determines whether the CLK input is enabled. The next rising edge
of the CLK signal will be valid when is CKE HIGH and invalid when LOW. When CKE
is LOW, the device will be in either power-down mode, clock suspend mode, or self
refresh mode. CKE is an asynchronous input.
CLK is the master clock input for this device. Except for CKE, all inputs to this device
are acquired in synchronization with the rising edge of this pin.
The CS input determines whether command input is enabled within the device.
Command input is enabled when
CS is LOW, and disabled with CS is HIGH. The
device remains in the previous state when
CS
is HIGH.
DQ0 to DQ15 are I/O pins. I/O through these pins can be controlled in byte units
using the LDQM and UDQM pins.
BA0, BA1
CAS
CKE
20, 21
17
37
CLK
CS
38
19
Input Pin
Input Pin
DQ0 to
DQ15
LDQM,
UDQM
2, 4, 5, 7, 8, 10,
11,13, 42, 44, 45,
47, 48, 50, 51, 53
15, 39
DQ Pin
Input Pin
RAS
WE
V
DDq
V
DD
GND
q
GND
18
16
3, 9, 43, 49
1, 14, 27
6, 12, 46, 52
28, 41, 54
LDQM and UDQM control the lower and upper bytes of the I/O buffers. In read
mode, LDQM and UDQM control the output buffer. When LDQM or UDQM is LOW,
the corresponding buffer byte is enabled, and when HIGH, disabled. The outputs
go to the HIGH impedance state when LDQM/UDQM is HIGH. This function cor-
responds to
OE in conventional DRAMs. In write mode, LDQM and UDQM control
the input buffer. When LDQM or UDQM is LOW, the corresponding buffer byte is en-
abled, and data can be written to the device. When LDQM or UDQM is HIGH, input
data is masked and cannot be written to the device.
Input Pin
RAS,
in conjunction with
CAS
and
WE,
forms the device command. See the "Com-
mand Truth Table" item for details on device commands.
Input Pin
WE,
in conjunction with
RAS
and
CAS,
forms the device command. See the "Com-
mand Truth Table" item for details on device commands.
Power Supply Pin V
DDq
is the output buffer power supply.
Power Supply Pin V
DD
is the device internal power supply.
Power Supply Pin GND
q
is the output buffer ground.
Power Supply Pin GND is the device internal ground.
Integrated Silicon Solution, Inc. — www.issi.com
Rev. A
03/19/08
3
ISSI [ INTEGRATED SILICON SOLUTION, INC ]
