A43L4616AV-7F AMIC, A43L4616AV-7F Datasheet - Page 15

• Manufacturer Part Number: A43L4616AV-7F
• Description: 58T1327
• Manufacturer: AMIC

Specifications of A43L4616AV-7F

• Memory Type: SDRAM
• Memory Configuration: 16M X 16
• Access Time: 5.4ns
• Interface Type: LVTTL
• Memory Case Style: TSOPII
• No. Of Pins: 54
• Operating Temperature Range: 0°C To +70°C
• Frequency: 143MHz
• Rohs Compliant: Yes

Device Operations (continued)
Auto Precharge
The precharge operation can also be performed by using
auto precharge. The SDRAM internally generates the timing
to satisfy t
and CAS latency. The auto precharge command is issued at
the same time as burst read or burst write by asserting high
on A10/AP. If burst read or burst write command is issued
with low on A10/AP, the bank is left active until a new
command is asserted. Once auto precharge command is
given, no new commands are possible to that particular bank
until the bank achieves idle state.
Four Banks Precharge
All banks can be precharged at the same time by using
Precharge all command. Asserting low on
t
the end of tRP after performing precharge all, both banks are
in idle state.
Auto Refresh
The storage cells of SDRAM need to be refreshed every
64ms to maintain data. An auto refresh cycle accomplishes
refresh of a single row of storage cells. The internal counter
increments automatically on every auto refresh cycle to
refresh all the rows. An auto refresh command is issued by
asserting low on
both banks being in idle state and the device is not in power
down mode (CKE is high in the previous cycle). The time
PRELIMINARY
WE
WE
RAS
(min) requirement, performs precharge on both banks. At
. The auto refresh command can only be asserted with
with high on A10/AP after both banks have satisfied
RAS
(min) and “t
CS
(May, 2010, Version 0.4)
,
RAS
RP
” for the programmed burst length
and
CAS
with high on CKE and
CS
,
RAS
and
14
required to complete the auto refresh operation is specified
by “t
can be calculated by driving “t
then rounding up to the next higher integer. The auto refresh
command must be followed by NOP’s until the auto refresh
operation is completed. Both banks will be in the idle state at
the end of auto refresh operation. The auto refresh is the
preferred refresh mode when the SDRAM is being used for
normal data transactions. The auto refresh cycle can be
performed once in 15.6us or a burst of 8192 auto refresh
cycles once in 64ms.
Self Refresh
The self refresh is another refresh mode available in the
SDRAM. The self refresh is the preferred refresh mode for
data retention and low power operation of SDRAM. In self
refresh mode, the SDRAM disables the internal clock and all
the input buffers except CKE. The refresh addressing and
timing is internally generated to reduce power consumption.
The self refresh mode is entered from all banks idle state by
asserting low on
being low matters, all the other inputs including clock are
ignored to remain in the self refresh.
The self refresh is exited by restarting the external clock and
then asserting high on CKE. This must be followed by NOP’s
for a minimum time of “t
state to begin normal operation. If the system uses burst auto
refresh during normal operation, it is recommended to used
burst 8192 auto refresh cycles immediately after exiting self
refresh.
WE . Once the self refresh mode is entered, only CKE state
RC
(min)”. The minimum number of clock cycles required
CS
,
RAS
RC
AMIC Technology, Corp.
” before the SDRAM reaches idle
,
RC
CAS
” with clock cycle time and
and CKE with high on
A43L4616A