em636165 Etron Technology Inc., em636165 Datasheet - Page 10

• Manufacturer Part Number: em636165
• Description: 1m X 16 Bit Synchronous Dram Sdram
• Manufacturer: Etron Technology Inc.

Etron Confidential
5
6
Read and AutoPrecharge command
(RAS# = "H", CAS# = "L", WE# = "H", A11 = “V”, A10 = "H", A0-A7 = Column Address)
the read operation. Once this command is given, any subsequent command cannot occur within a
time delay of { t
command and the auto precharge function is ignored.
Write command
(RAS# = "H", CAS# = "L", WE# = "L", A11 = “V”, A10 = "L", A0-A7 = Column Address)
row in an active bank. The bank must be active for at least t
issued. During write bursts, the first valid data-in element will be registered coincident with the Write
command. Subsequent data elements will be registered on each successive positive clock edge
(refer to the following figure). The DQs remain with high-impedance at the end of the burst unless
another command is initiated. The burst length and burst sequence are determined by the mode
register, which is already programmed. A full-page burst will continue until terminated (at the end of
the page it will wrap to column 0 and continue).
BankPrecharge/PrechargeAll, or Read command before the end of the burst length. An interrupt
coming from Write command can occur on any clock cycle following the previous Write command
(refer to the following figure).
CLK
t
t
ADDRESS
COMMAND
CAS# latency=2
CAS# latency=3
CK2,
CK3,
The Read and AutoPrecharge command automatically performs the precharge operation after
The Write command is used to write a burst of data on consecutive clock cycles from an active
A write burst without the auto precharge function may be interrupted by a subsequent Write,
DQ
DQ
’
’
s
s
Burst Write Operation
RP
(min.) + burst length } . At full-page burst, only the read operation is performed in this
READ A
T0
Bank,
Col A
Read to Precharge
T1
NOP
DOUT A
T2
NOP
(Burst Length = 4, CAS# Latency = 2, 3)
0
DOUT A
DOUT A
10
T3
NOP
(CAS# Latency = 2, 3)
1
0
DOUT A
DOUT A
Bank(s)
Precharge
T4
2
1
DOUT A
DOUT A
T5
RCD
NOP
(min.) before the Write command is
tRP
2
3
DOUT A
T6
NOP
3
Rev. 3.4
T7
Activate
EM636165
Bank
Row
T8
NOP
Apr. 2008