MT48V16M16LFFG Datasheet, PDF (29/58 Pages) Micron Technology – MOBILE SDRAM

ADVANCE
256Mb: x16
MOBILE SDRAM
TRUTH TABLE 3 – CURRENT STATE BANK n, COMMAND TO BANK n
(Notes: 1-6; notes appear below and on next page)
CURRENT STATE CS# RAS# CAS# WE#
Any
HXXX
L HHH
L L HH
Idle
L L LH
LLLL
L LHL
LHLH
Row Active
LHL L
L LHL
Read
LHLH
(Auto
LHL L
Precharge
L LHL
Disabled)
L HHL
Write
LHLH
(Auto
LHL L
Precharge
L LHL
Disabled)
L HH L
COMMAND (ACTION)
COMMAND INHIBIT (NOP/Continue previous operation)
NO OPERATION (NOP/Continue previous operation)
ACTIVE (Select and activate row)
AUTO REFRESH
LOAD MODE REGISTER
PRECHARGE
READ (Select column and start READ burst)
WRITE (Select column and start WRITE burst)
PRECHARGE (Deactivate row in bank or banks)
READ (Select column and start new READ burst)
WRITE (Select column and start WRITE burst)
PRECHARGE (Truncate READ burst, start PRECHARGE)
DEEP POWER DOWN
READ (Select column and start READ burst)
WRITE (Select column and start new WRITE burst)
PRECHARGE (Truncate WRITE burst, start PRECHARGE)
BURST TERMINATE
NOTES
7
7
11
10
10
8
10
10
8
9
10
10
8
9
NOTE:
1. This table applies when CKE_n-1 was HIGH and CKE_n is HIGH (see Truth Table 2) and after ^tXSR has been
met (if the previous state was self refresh).
2. This table is bank-specific, except where noted, i.e., the current state is for a specific bank and the commands shown
are those allowed to be issued to that bank when in that state. Exceptions are covered in the notes below.
3. Current state definitions:
Idle: The bank has been precharged, and ^tRP has been met.
Row Active: A row in the bank has been activated, and ^tRCD has been met. No data bursts/accesses and no
register accesses are in progress.
Read: A READ burst has been initiated, with auto precharge disabled, and has not yet terminated or
been terminated.
Write: A WRITE burst has been initiated, with auto precharge disabled, and has not yet terminated
or been terminated.
4. The following states must not be interrupted by a command issued to the same bank. COMMAND INHIBIT or NOP
commands, or allowable commands to the other bank should be issued on any clock edge occurring during these states.
Allowable commands to the other bank are determined by its current state and Truth Table 3, and according to Truth
Table 4.
Precharging: Starts with registration of a PRECHARGE command and ends when ^tRP is met. Once ^tRP is met,
the bank will be in the idle state.
Row Activating: Starts with registration of an ACTIVE command and ends when ^tRCD is met. Once ^tRCD is met,
the bank will be in the row active state.
Read w/Auto
Precharge Enabled: Starts with registration of a READ command with auto precharge enabled and ends when ^tRP
has been met. Once ^tRP is met, the bank will be in the idle state.
Write w/Auto
Precharge Enabled: Starts with registration of a WRITE command with auto precharge enabled and ends when ^tRP
has been met. Once ^tRP is met, the bank will be in the idle state.
256Mb: x16 Mobile SDRAM
MobileRamY26L_A.p65 – Pub. 5/02
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©2002, Micron Technology, Inc.