PD45128441-I Datasheet, PDF (10/89 Pages) Elpida Memory – 128M-bit Synchronous DRAM 4-bank, LVTTL WTR (Wide Temperature Range)

µPD45128441-I, 45128841-I, 45128163-I
1. Input / Output Pin Function
Pin name
Input / Output
Function
CLK
CKE
Input
Input
/CS
/RAS, /CAS, /WE
A0 - A11
Input
Input
Input
CLK is the master clock input. Other inputs signals are referenced to the CLK rising
edge.
CKE determine validity of the next CLK (clock). If CKE is high, the next CLK rising edge
is valid; otherwise it is invalid. If the CLK rising edge is invalid, the internal clock is not
issued and the µPD45128xxx suspends operation.
When the µPD45128xxx is not in burst mode and CKE is negated, the device enters
power down mode. During power down mode, CKE must remain low.
/CS low starts the command input cycle. When /CS is high, commands are ignored but
operations continue.
/RAS, /CAS and /WE have the same symbols on conventional DRAM but different
functions. For details, refer to the command table.
Row Address is determined by A0 - A11 at the CLK (clock) rising edge in the active
command cycle. It does not depend on the bit organization.
Column Address is determined by A0 - A9, A11 at the CLK rising edge in the read or
write command cycle. It depends on the bit organization: A0 - A9, A11 for ×4 device, A0
- A9 for ×8 device, A0 - A8 for ×16 device.
A10 defines the precharge mode. When A10 is high in the precharge command cycle,
all banks are precharged; when A10 is low, only the bank selected by BA0(A13) and
BA1(A12) is precharged.
When A10 is high in read or write command cycle, the precharge starts automatically
after the burst access.
BA0, BA1
Input
DQM, UDQM, LDQM Input
BA0(A13) and BA1(A12) are the bank select signal. In command cycle, BA0(A13) and
BA1(A12) low select bank A, BA0(A13) high and BA1(A12) low select bank B, BA0(A13)
low and BA1(A12) high select bank C and then BA0(A13) and BA1(A12) high select
bank D.
DQM controls I/O buffers. In ×16 products, UDQM and LDQM control upper byte and
lower byte I/O buffers, respectively.
In read mode, DQM controls the output buffers like a conventional /OE pin.
DQM high and DQM low turn the output buffers off and on, respectively.
The DQM latency for the read is two clocks.
In write mode, DQM controls the word mask. Input data is written to the memory cell if
DQM is low but not if DQM is high.
The DQM latency for the write is zero.
DQ0 - DQ15
VCC, VSS, VCCQ, VSSQ
Input / Output DQ pins have the same function as I/O pins on a conventional DRAM.
(Power supply) VCC and VSS are power supply pins for internal circuits. VCCQ and VSSQ are power
supply pins for the output buffers.
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Preliminary Data Sheet E0233N10