GS4576S09/18L
Ball Descriptions
Symbol
A0–A21
BA0–B2
CK, CK
Type
Input
Input
Input
Input
Input
Description
Address Inputs—A0–A21
define the row and column addresses for Read and Write Operations. During
a Mode Register Set (MRS), the address inputs define the register settings. They are sampled at the
rising edge of CK.
Bank Address inputs—Select
to which internal bank a command is being applied.
Input Clock—CK
and CK are differential input clocks. Addresses and commands are latched on the
rising edge of CK. CK is ideally 180º out of phase with CK.
Chip Select—CS
enables the command decoder when Low and disables it when High. When the
command decoder is disabled, new commands are ignored, but internal operations continue.
Data Input—The
D signals form the 18-bit input data bus. During Write commands, the data is sampled
at both edges of DK.
Input Data Clock—DK
and DK are the differential input data clocks. All input data is referenced to both
edges of DK. DK is ideally 180º out of phase with DK. In both the x9 and x18 devices, all Ds are
referenced to DK and DK.
Input Data Mask—The
DM signal is the input mask signal for Write data. Input data is masked when DM
is sampled High. DM is sampled on both edges of DK. Tie signal to ground if not used.
IEEE 1149.1 clock input—This
ball must be tied to V
SS
if the JTAG function is not used.
IEEE 1149.1 test inputs—These
balls may be left as no connects if the JTAG function is not used.
Command Inputs—Sampled
at the positive edge of CK, WE and REF define (together with CS) the
command to be executed.
Input Reference Voltage—Nominally
V
DDQ
/2. Provides a reference voltage for the input buffers.
External Impedance (25–60)—This
signal is used to tune the device outputs to the system data bus
impedance. Q output impedance is set to 0.2 * RQ, where RQ is a resistor from this signal to ground.
Connecting ZQ to GND invokes the Minimum Impedance mode. Connecting ZQ to V
DD
invokes the
maximum Impedance mode. Refer to the Mode Register Definition diagrams (Mode Register Bit 8 (M8))
to activate or deactivate this function.
Q0–Q17
Output
Data Output—The
Q signals form the 18-bit output data bus. During Read commands, the data is
referenced to both edges of QK.
Output Data Clocks—QKx
and QKx are opposite polarity, output data clocks. They are free running,
and during Reads, are edge-aligned with data output from the LLDRAM II. QKx is ideally 180º out of
phase with QKx. For the x18 device, QK0 and QK0 are aligned with Q0–Q8, while QK1 and QK1 are
aligned with Q9–Q17. For the x9 device, all Qs are aligned with QK0 and QK0.
CS
D0–D17
DK, DK
Input
DM
TCK
TMS, TDI
WE, REF
V
REF
Input
Input
Input
Input
Input
ZQ
I/O
QKx, QKx
Output
Rev: 1.03 11/2013
4/63
© 2011, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
GSI [ GSI TECHNOLOGY ]
