A45L9332AE-6 AMIC Technology, Corp., A45L9332AE-6 Datasheet - Page 15

• Manufacturer Part Number: A45L9332AE-6
• Description: 256K x 32 Bit x 2 Banks Synchronous Graphic RAM
• Manufacturer: AMIC Technology, Corp.

Device Operations
Clock (CLK)
The clock input is used as the reference for all SGRAM
operations. All operations are synchronized to the positive
going edge of the clock. The clock transitions must be
monotonic between VIL and VIH. During operation with
CKE high all inputs are assumed to be in valid state (low or
high) for the duration of set up and hold time around
positive edge of the clock for proper functionality and ICC
specifications.
Clock Enable (CLK)
The clock enable (CKE) gates the clock onto SGRAM. If
CKE goes low synchronously with clock (set-up and hold
time same as other inputs), the internal clock is suspended
form the next clock cycle and the state of output and burst
address is frozen as long as the CKE remains low. All other
inputs are ignored from the next clock cycle after CKE goes
low. When both banks are in the idle state and CKE goes
low synchronously with clock, the SGRAM enters the power
down mode form the next clock cycle. The SGRAM remains
in the power down mode ignoring the other inputs as long
as CKE remains low. The power down exit is synchronous
as the internal clock is suspended. When CKE goes high at
least “t
clock, then the SGRAM becomes active from the same
clock edge accepting all the input commands.
Bank Select (A10)
This SGRAM is organized as two independent banks of
262,144 words X 32 bits memory arrays. The A10 inputs is
latched at the time of assertion of RAS and
the bank to be used for the operation. When A10 is
asserted low, bank A is selected. When A10 is asserted
high, bank B is selected. The bank select A10 is latched at
bank activate, read, write mode register set and precharge
operations.
Address Input (A0 ~ A9)
The 18 address bits required to decode the 262,144 word
locations are multiplexed into 10 address input pins
(A0~A9). The 10 bit row address is latched along with
column address is latched along with
during read or write command.
NOP and Device Deselect
When RAS ,
performs no operation (NOP). NOP does not initiate any
new operation, but is needed to complete operations which
require more than single clock like bank activate, burst
PRELIMINARY
RAS and A10 during bank activate command. The 8 bit
SS
+ 1
CLOCK
CAS
(October, 2001, Version 0.1)
” before the high going edge of the
and
WE
are high, the SGRAM
CAS
,
CAS
WE
to select
and A10
14
read, auto refresh, etc. The device deselect is also a NOP
and is entered by asserting CS high. CS high disables
the command decoder so that RAS ,
and all the address inputs are ignored.
Power-Up
The following sequence is recommended for POWER UP
1. Power must be applied to either CKE and DQM inputs to
2. After VDD reaches the desired voltage, a minimum
3. Both banks must be precharged now.
4. Perform a minimum of 2 Auto refresh cycles to stabilize
5. Perform a MODE REGISTER SET cycle to program the
Mode Register Set (MRS)
The mode register stores the data for controlling the various
operation modes of SGRAM. It programs the CAS latency,
addressing mode, burst length, test mode and various
vendor specific options to make SGRAM useful for variety
of different applications. The default value of the mode
register is not defined, therefore the mode register must be
written after power up to operate the SGRAM. The mode
register is written by asserting low on CS
mode with CKE already high prior to writing the mode
register). The state of address pins A0~A9 and A10 in the
same cycle as CS , RAS ,
is the data written in the mode register. One clock cycle is
required to complete the write in the mode register. The
mode register contents can be changed using the same
command and clock cycle requirements during operation as
long as both banks are in the idle state. The mode register
is divided into various fields depending on functionality. The
burst length field uses A0~A2, burst type uses A3,
addressing mode uses A4~A6, A7~A8 and A10 are used
for vendor specific options or test mode. And the write burst
length is programmed using A9. A7~A8 and A10 must be
set to low for normal SGRAM operation.
Refer to table for specific codes for various burst length,
addressing modes and CAS latencies.
CAS
pull them high and other pins are NOP condition at the
inputs before or along with VDD (and VDDQ) supply.
The clock signal must also be asserted at the same time.
pause of 200 microseconds is required with inputs in
NOP condition.
the internal circuitry.
CAS latency, burst length and burst type as the default
value of mode register is undefined.
At the end of one clock cycle from the mode register set
cycle, the device is ready for operation.
When the above sequence is used for Power-up, all the
out-puts will be in high impedance state. The high
impedance of outputs is not guaranteed in any other
power-up sequence.
Cf.) Sequence of 4 & 5 may be charged.
,
WE
and DSF (The SGRAM should be in active
AMIC Technology, Inc.
CAS
A45L9332A Series
,
WE
CAS
and DSF going low
and
WE
, RAS ,
, DSF