6Preliminary Data Sheet M15823EJ2V0DS
µ
µµ
µ
PD44164085, 44164185, 44164365
Pin Identification
Symbol Description
A Synchronous Address I nputs: These i nputs are registered and must meet the setup and hold times around the
rising edge of K. Balls 9A, 3A, 10A, and 2A are reserved for the next higher-order address i nputs on fut ure
devices. All trans actions operate on a burst of two words (one clock period of bus activity). These inputs are
ignored when device is deselected.
/LD Synchronous Load: This input is brought LOW when a bus cycle sequence is to be defined. This definition
includes address and read/write direction. All transact i ons operate on a burst of 2 data (one clock periods of
bus activit y).
R, /W Synchronous Read/W rite Input: When /LD is LOW, this input designates the access type (READ when /R, W is
HIGH, WRITE when /R, W is LOW) for the loaded address. /R, W must meet the setup and hold times around
the rising edge of K.
/NWx
/BWx Synchronous Byte W rites (Nybble Writes on x8): When LOW these inputs cause their respective byte or nybbl e
to be registered and written during WRITE cycles. These signals must meet setup and hold times around the
rising edges of K and /K for each of the two rising edges comprising the WRITE cycle. See Pin Confi gurations
for signal t o data relationships.
K, /K Input Clock: This input clock pair registers address and control inputs on the rising edge of K, and registers data
on the rising edge of K and the rising edge of /K. /K is ideally 180 degrees out of phase with K. All synchronous
inputs must meet setup and hol d times around the clock risi ng edges.
C, /C Output Clock: This clock pair provides a user controlled means of tuning device output data. The rising edge of
C is used as the output timing reference for first output dat a. The risi ng edge of /C is used as the output
reference f or second output dat a. Ideally, /C is 180 degrees out of phas e with C. C and /C may be tied HIGH to
force the use of K and /K as the output reference clocks instead of having to provide C and /C clocks. If tied
HIGH, C and /C must remain HIGH and not be toggled during device operation.
/DLL DLL Disable: When LOW, this input causes the DLL to be bypassed f or stable low frequency operat i on.
ZQ Output Impedance Matching Input: This input is used to tune the device outputs to the system data bus
impedance. DQ and CQ output impedance are set to 0.2 x RQ, where RQ is a resistor from this bump to
ground. Alternat el y, this pi n can be connect ed directl y t o VDDQ, which enables the minimum impedance mode.
This pin cannot be connected directly to GND or left unconnected.
TMS
TDI IEEE 1149.1 Test Inputs: 1.8V I/O levels. These balls may be left Not Connected if the JTAG function is not
used in the circuit.
TCK IEEE 1149.1 Clock Input: 1.8V I/O levels. This pin must be tied to VSS if the JTAG function is not used in the
circuit.
VREF HSTL Input Reference Voltage: Nominally VDDQ/2. Provides a referenc e voltage for t he input buffers.
D0 to Dxx Synchronous Data Inputs: Input data must meet setup and hold times around the risi ng edges of K and /K
during WRITE operations. See Pin Configurations for ball site locat i on of individual signals .
x8 device uses D0-D7. Rem aining signal s are NC.
x18 device uses D0-D17. Rem ai ni ng signals are NC.
x36 device uses D0-D35.
NC signals are read in the JTAG scan chain as the logic level appli ed to the ball site.
CQ, /CQ Synchronous Echo Clock Outputs. The ris i ng edges of these outputs are tightl y m atched to the sync hronous
data outputs and can be used as a data valid indication. These signals run f reel y and do not stop when Q
tristates.
TDO IEEE 1149.1 Test Output: 1.8V I/O level.
Q0 to Qxx Synchronous Data Outputs: Output data is synchronized to the respective C and /C or to K and /K ris i ng edges
if C and /C are tied HIGH. This bus operates in response to /R commands. See Pin Configurations for ball sit e
locati on of individual signals .
x8 device uses Q0-Q7. Remainin g signals are NC.
x18 device uses Q0-Q17. Remaining signals are NC.
x36 device uses Q0-Q35.
NC signals are read in the JTAG scan chain as the logic l evel applied to the ball site.
VDD Power Supply: 1.8V nomi nal. See DC Characteris tics and Operating Conditions for range.
VDDQ Power Supply: Isol ated Output Buffer Supply. Nominally 1.5V. 1.8V is also permiss i bl e. S ee DC Characteristics
and Operating Conditi ons for range.
VSS Power Supply: Ground
NC No Connect: These signals are internally connected and appear in the JTAG scan chain as the logic level
applied to the ball sit es. These signals m ay be connect ed to ground to improve package heat dissipation.
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