hm5264165f-75 Elpida Memory, Inc., hm5264165f-75 Datasheet - Page 9

• Manufacturer Part Number: hm5264165f-75
• Description: 64m Lvttl Interface Sdram
• Manufacturer: Elpida Memory, Inc.

Pin Functions
CLK (input pin): CLK is the master clock input to this pin. The other input signals are referred at CLK
rising edge.
CS (input pin): When CS is Low, the command input cycle becomes valid. When CS is High, all inputs are
ignored. However, internal operations (bank active, burst operations, etc.) are held.
RAS, CAS, and WE (input pins): Although these pin names are the same as those of conventional DRAMs,
they function in a different way. These pins define operation commands (read, write, etc.) depending on the
combination of their voltage levels. For details, refer to the command operation section.
A0 to A11 (input pins): Row address (AX0 to AX11) is determined by A0 to A11 level at the bank active
command cycle CLK rising edge.
HM5264805F, AY0 to AY9; HM5264405F) is determined by A0 to A7, A8 or A9 (A7; HM5264165F, A8;
HM5264805F, A9; HM5264405F) level at the read or write command cycle CLK rising edge. And this
column address becomes burst access start address. A10 defines the precharge mode. When A10 = High at
the precharge command cycle, all banks are precharged. But when A10 = Low at the precharge command
cycle, only the bank that is selected by A12/A13 (BS) is precharged. For details refer to the command
operation section.
A12/A13 (input pins): A12/A13 are bank select signal (BS). The memory array of the HM5264165F,
HM5264805F, the HM5264405F is divided into bank 0, bank 1, bank 2 and bank 3. HM5264165F contain
4096-row
contain 4096-row
and A13 is Low, bank 1 is selected. If A12 is Low and A13 is High, bank 2 is selected. If A12 is High and
A13 is High, bank 3 is selected.
CKE (input pin): This pin determines whether or not the next CLK is valid. If CKE is High, the next CLK
rising edge is valid. If CKE is Low, the next CLK rising edge is invalid. This pin is used for power-down
mode, clock suspend mode and self refresh mode.
DQM, DQMU/DQML (input pins): DQM, DQMU/DQML controls input/output buffers.
Read operation: If DQM, DQMU/DQML is High, the output buffer becomes High-Z. If the DQM,
DQMU/DQML is Low, the output buffer becomes Low-Z. (The latency of DQM, DQMU/DQML during
reading is 2 clocks.)
Write operation: If DQM, DQMU/DQML is High, the previous data is held (the new data is not written). If
DQM, DQMU/DQML is Low, the data is written. (The latency of DQM, DQMU/DQML during writing is 0
clock.)
DQ0 to DQ15 (DQ pins): Data is input to and output from these pins (DQ0 to DQ15; HM5264165F, DQ0
to DQ7; HM5264805F, DQ0 to DQ3; HM5264405F).
V
output buffer.)
CC
and V
CC
256-column
Q (power supply pins): 3.3 V is applied. (V
1024-column
HM5264165F/HM5264805F/HM5264405F-75/A60/B60
16-bit. HM5264805F contain 4096-row
Data Sheet E0135H10
4-bit. If A12 is Low and A13 is Low, bank 0 is selected. If A12 is High
Column address (AY0 to AY7; HM5264165F, AY0 to AY8;
CC
is for the internal circuit and V
512-column
8-bit. HM5264405F
CC
Q is for the
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