K4S643232C Datasheet, PDF (23/43 Pages) Samsung semiconductor – 2M x 32 SDRAM 512K x 32bit x 4 Banks Synchronous DRAM LVTTL

K4S643232C
CMOS SDRAM
FUNCTION TRUTH TABLE (TABLE 1)
Current
State
CS
RAS
CAS
WE
BA
L
L
L
X
X
H
X
X
X
X
L
H
H
H
X
Row
L
H
H
L
X
Activating
L
H
L
X
BA
L
L
H
H
BA
L
L
H
L
BA
L
L
L
X
X
H
X
X
X
X
L
H
H
X
X
Refreshing
L
H
L
X
X
L
L
H
X
X
L
L
L
X
X
H
X
X
X
X
Mode
L
H
H
H
X
Register
L
H
H
L
X
Accessing
L
H
L
X
X
L
L
X
X
X
ADDR
X
X
X
X
CA
RA
A10/AP
X
X
X
X
X
X
X
X
X
X
X
ACTION
ILLEGAL
NOP --> Row Active after tRCD
NOP --> Row Active after tRCD
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
NOP --> Idle after tRFC
NOP --> Idle after tRFC
ILLEGAL
ILLEGAL
ILLEGAL
NOP --> Idle after 2 clocks
NOP --> Idle after 2 clocks
ILLEGAL
ILLEGAL
ILLEGAL
Abbreviations : RA = Row Address
NOP = No Operation Command
BA = Bank Address
CA = Column Address
AP = Auto Precharge
Note
2
2
2
2
*Note : 1. All entries assume the CKE was active (High) during the precharge clcok and the current clock cycle.
2. Illegal to bank in specified state ; Function may be Iegal in the bank indicated by BA, depending on the
state of that bank.
3. Must satisfy bus contention, bus turn around, and/or write recovery requirements.
4. NOP to bank precharging or in idle state. May precharge bank indicated by BA (and A10/AP).
5. Illegal if any bank is not idle.
- 23
REV. 1.1 Nov. '99