- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄363913 > WEDPNF8M721V-1012BC (Electronic Theatre Controls, Inc.) 8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package PDF資料下載
參數(shù)資料
| 型號： | WEDPNF8M721V-1012BC |
| 廠商： | Electronic Theatre Controls, Inc. |
| 英文描述： | 8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
| 中文描述： | 8Mx72同步DRAM 8MB閃存的混合模塊多芯片封裝 |
| 文件頁數(shù)： | 8/42頁 |
| 文件大小： | 1276K |
| 代理商： | WEDPNF8M721V-1012BC |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁當(dāng)前第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁
8
White Electronic Designs Corporation Phoenix AZ (602) 437-1520
White Electronic Designs
WEDPNF8M721V-XBX
Accesses begin with the registration of an ACTIVE com-
mand which is then followed by a READ or WRITE com-
mand. The address bits registered coincident with the AC-
TIVE command are used to select the bank and row to be
accessed (BA0 and BA1 select the bank, A0-11 select the
row). The address bits (A0-8) registered coincident with
the READ or WRITE command are used to select the start-
ing column location for the burst access.
Prior to normal operation, the SDRAM must be initialized.
The following sections provide detailed information cover-
ing device initialization, register definition, command de-
scriptions and device operation.
INITIALIZATION
SDRAMs must be powered up and initialized in a predefined
manner. Operational procedures other than those speci-
fied may result in undefined operation. Once power is ap-
plied to VDD and VDDQ (simultaneously) and the clock is
stable (stable clock is defined as a signal cycling within tim-
ing constraints specified for the clock pin), the SDRAM re-
quires a 100μs delay prior to issuing any command other
than a COMMAND INHIBIT or a NOP. Starting at some point
during this 100μs period and continuing at least through
the end of this period, COMMAND INHIBIT or NOP com-
mands should be applied.
Once the 100μs delay has been satisfied with at least one
COMMAND INHIBIT or NOP command having been applied,
a PRECHARGE command should be applied. All banks must
be precharged, thereby placing the device in the all banks
idle state.
Once in the idle state, two AUTO REFRESH cycles must be
performed. After the AUTO REFRESH cycles are complete, the
SDRAM is ready for Mode Register programming. Because the
Mode Register will power up in an unknown state, it should
be loaded prior to applying any operational command.
REGISTER DEFINITION
MODE REGISTER
The Mode Register is used to define the specific mode of
operation of the SDRAM. This definition includes the selec-
tion of a burst length, a burst type, a CAS latency, an oper-
ating mode and a write burst mode, as shown in Figure 3.
The Mode Register is programmed via the LOAD MODE REG-
ISTER command and will retain the stored information until
it is programmed again or the device loses power.
Mode register bits M0-M2 specify the burst length, M3
specifies the type of burst (sequential or interleaved), M4-
M6 specify the CAS latency, M7 and M8 specify the oper-
ating mode, M9 specifies the WRITE burst mode, and M10
and M11 are reserved for future use.
The Mode Register must be loaded when all banks are idle,
and the controller must wait the specified time before initi-
ating the subsequent operation. Violating either of these
requirements will result in unspecified operation.
BURST LENGTH
Read and write accesses to the SDRAM are burst oriented,
with the burst length being programmable, as shown in Fig-
ure 3. The burst length determines the maximum number of
column locations that can be accessed for a given READ or
WRITE command. Burst lengths of 1, 2, 4 or 8 locations are
available for both the sequential and the interleaved burst
types, and a full-page burst is available for the sequential
type. The full-page burst is used in conjunction with the
BURST TERMINATE command to generate arbitrary burst
lengths.
Reserved states should not be used, as unknown opera-
tion or incompatibility with future versions may result.
When a READ or WRITE command is issued, a block of col-
umns equal to the burst length is effectively selected. All
accesses for that burst take place within this block, mean-
ing that the burst will wrap within the block if a boundary is
reached. The block is uniquely selected by A1-8 when the
burst length is set to two; by A2-8 when the burst length is
set to four; and by A3-8 when the burst length is set to
eight. The remaining (least significant) address bit(s) is (are)
used to select the starting location within the block. Full-
page bursts wrap within the page if the boundary is reached.
BURST TYPE
Accesses within a given burst may be programmed to be
either sequential or interleaved; this is referred to as the
burst type and is selected via bit M3.
The ordering of accesses within a burst is determined by
the burst length, the burst type and the starting column
address, as shown in Table 1.
CAS LATENCY
The CAS latency is the delay, in clock cycles, between the
registration of a READ command and the availability of the
first piece of output data. The latency can be set to two or
three clocks.
If a READ command is registered at clock edge n and the
latency is m clocks, the data will be available by clock edge
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| WEDPNF8M721V-1012BI | 8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
| WEDPNF8M721V-1012BM | 8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
| WEDPNF8M721V-1015BC | 8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
| WEDPNF8M721V-1015BI | 8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
| WEDPNF8M721V-1015BM | 8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| WEDPNF8M721V-1012BI | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
| WEDPNF8M721V-1012BM | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
| WEDPNF8M721V-1015BC | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
| WEDPNF8M721V-1015BI | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
| WEDPNF8M721V-1015BM | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8Mx72 Synchronous DRAM + 8Mb Flash Mixed Module Multi-Chip Package |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。