HYB39S16400 Datasheet, PDF (4/22 Pages) Siemens Semiconductor Group – 16 MBit Synchronous DRAM

HYB 39S16400/800/160AT-8/-10
16 MBit Synchronous DRAM
Signal Pin Description
Pin
Type Signal Polarity Function
CLK
Input Pulse Positive The system clock input. All of the SDRAM inputs are
Edge sampled on the rising edge of the clock.
CKE
Input
Level Active
High
Activates the CLK signal when high and deactivates the
CLK signal when low, thereby initiates either the Power
Down mode, Suspend mode or the Self Refresh mode.
CS
Input Pulse Active CS enables the command decoder when low and disables
Low
the command decoder when high. When the command
decoder is disabled, new commands are ignored but
previous operations continue.
RAS
CAS
WE
Input
Pulse Active
Low
When sampled at the positive rising edge of the clock,
CAS, RAS and WE define the command to be executed by
the SDRAM.
A0 - A10 Input Level –
During a Bank Activate command cycle, A0 - A10 defines
the row address (RA0 - RA10) when sampled at the rising
clock edge.
During a Read or Write command cycle, A0 - A9 defines
the column address (CA0 - CAn) when sampled at the
rising clock edge. CAn depends from the SDRAM
organisation.
4M × 4 SDRAM CAn = CA9
2M × 8 SDRAM CAn = CA8
1M × 16 SDRAM CAn = CA7
In addition to the column address, A10 is used to invoke
autoprecharge operation at the end of the burst read or
write cycle. If A10 is high, autoprecharge is selected and
A11 defines the bank to be precharged (low = bank A,
high = bank B). If A10 is low, autoprecharge is disabled.
During a Precharge command cycle, A10 is used in
conjunction with A11 to control which bank(s) to
precharge. If A10 is high, both bank A and bank B will be
precharged regardless of the state of A11. If A10 is low,
then A11 is used to define which bank to precharge.
A11 (BS) Input Level –
Selects which bank is to be active. A11 low selects bank A
and A11 high selects bank B.
DQx
Input Level –
Output
Data Input/Output pins operate in the same manner as on
conventional DRAMs.
Semiconductor Group
4
1998-10-01