GM72V66841CT-7K Ver la hoja de datos (PDF) - LG

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GM72V66841CT-7K

2,097,152 WORD x 8 BIT x 4 BANK SYNCHRONOUS DYNAMIC RAM

LG 

LG Semicon

Auto-refresh command[REF]: When this

command is input from the IDLE state, the

synchronous DRAM starts auto-refresh

operation. (The auto-refresh is the same as the

CBR refresh of conventional DRAMs.) During

the auto-refresh operation, refresh address and

bank select address are generated inside the

synchronous DRAM. For every auto-refresh

cycle, the internal address counter is updated.

Accordingly, 4,096 times are required to refresh

the entire memory. Before executing the auto-

refresh command, all the banks must be in the

IDLE state. In addition, since the Precharge for

all banks is automatically performed after auto-

refresh, no Precharge command is required after

auto-refresh.

Self-refresh entry[SELF]: When this command

is input during the IDLE state, the synchronous

DRAM starts self-refresh operation. After the

execution of this command, self-refresh

continues while CKE is Low. Since self-refresh

is performed internally and automatically,

external refresh operations are unnecessary.

GM72V66841CT/CLT

Self-refresh exit[SELFX]: When this command

is executed during self-refresh mode, the

synchronous DRAM can exit from self-refresh

mode. After exiting from self-refresh mode, the

synchronous DRAM enters the IDLE state.

Power down mode entry: When this command

is executed during the IDLE state, the

synchronous DRAM enters Power down mode.

In Power down mode, Power consumption is

suppressed by cutting off the initial input circuit.

Power down exit: When this command is

executed at the Power down mode, the

synchronous DRAM can exit from Power down

mode. After exiting from Power down mode, the

synchronous DRAM enters the IDLE state.

Function Truth Table

The following table shows the operations that are performed when each command is issued in each

mode of the synchronous DRAM.

Current

state

Precharge

CS RAS CAS WE Address

Command

Operation

H X X XX

L H H HX

DESL

NOP

Enter IDLE after tRP

Enter IDLE after tRP

L H H LX

BST

NOP

L H L H BA, CA, A10 READ/READ A ILLEGAL

L H L L BA, CA, A10 WRIT/WRIT A ILLEGAL

L L H H BA, RA

ACTV

ILLEGAL

L L H L BA, A10 PRE, PALL NOP

8

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