6Preliminary Data Sheet M15823EJ1V0DS
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µµ
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PD44164085, 44164185, 44164365
Pin Identification
Symbol Description
Ax Synchronous Address Inputs: These inputs 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 inputs on future
devices. All transactions 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 transactions operate on a burst of 2 data (one clock periods of
bus activity).
R , /W Synchronous Read/Write 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 Writes (Nybble Writes on x8): When LOW these inputs cause their respective byte or nybble
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 assignment
figures for signal to 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 hold times around the clock rising 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 data. The rising edge of /C is used as the output
reference for second output data. Ideally, /C is 180 degrees out of phase 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 for stable low frequency operation.
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. Alternately, this pin can be connected directly to VDD, 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 reference voltage for the input buffers.
D0 to Dxx Synchronous Data Inputs: Input data must meet setup and hold times around the rising edges of K and K#
during WRITE operations. See pin assignment figures for ball site location of individual signals.
x8 device uses D0-D7. Remaining signals are NC.
x18 device uses D0-D17. Remaining signals are NC.
x36 device uses D0-D35.
NC signals are read in the JTAG scan chain as the logic level applied to the ball site.
CQ, /CQ Synchronous Echo Clock Outputs. The rising edges of these outputs are tightly matched to the synchronous
data outputs and can be used as a data valid indication. These signals run freely 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 rising edges
if C and /C are tied HIGH. This bus operates in response to /R commands. See pin assignment figures for ball
site location of individual signals.
x8 device uses Q0-Q7. Remaining 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 level applied to the ball site.
VDD Power Supply: 1.8V nominal. See DC Electrical Characteristics and Operating Conditions for range.
VDDQ Power Supply: Isolated Output Buffer Supply. Nominally 1.5V. 1.8V is also permissible. See DC Electrical
Characteristics and Operating Conditions 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 sites. These signals may be connected to ground to improve package heat dissipation.