參數(shù)資料
型號(hào)： WEDPNF8M722V-1010BC
廠商： MICROSEMI CORP-PMG MICROELECTRONICS
元件分類： 存儲(chǔ)器
英文描述： SPECIALTY MEMORY CIRCUIT, PBGA275
封裝： 32 X 25 MM, PLASTIC, BGA-275
文件頁數(shù)： 42/43頁
文件大?。?/td> 1280K
代理商： WEDPNF8M722V-1010BC
8
White Electronic Designs Corporation Phoenix AZ (602) 437-1520
White Electronic Designs
WEDPNF8M722V-XBX
SDRAM FUNCTIONAL DESCRIPTION
INITIALIZATION
BURST LENGTH
BURST TYPE
REGISTER DEFINITION
MODE REGISTER
Read and write accesses to the SDRAM are burst oriented;
accesses start at a selected location and continue for a pro-
grammed number of locations in a programmed sequence.
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.
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 100s delay prior to issuing any command other
than a COMMAND INHIBIT or a NOP. Starting at some point
during this 100s period and continuing at least through
the end of this period, COMMAND INHIBIT or NOP com-
mands should be applied.
Once the 100s delay has been satisfied with at least one COM-
MAND 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.
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 speci-
fies the type of burst (sequential or interleaved), M4-M6
specify the CAS latency, M7 and M8 specify the operating
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.
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.
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 ad-
dress, as shown in Table 1.
相關(guān)PDF資料
PDF描述
WEDPNF8M722V-1210BM SPECIALTY MEMORY CIRCUIT, PBGA275
WEDPNF8M722V-1015BC SPECIALTY MEMORY CIRCUIT, PBGA275
WEDPNF8M722V-1212BM SPECIALTY MEMORY CIRCUIT, PBGA275
WEDPNF8M722V-1012BC SPECIALTY MEMORY CIRCUIT, PBGA275
WEDPZ512K72S-133BC 512K X 72 MULTI DEVICE SRAM MODULE, 4.2 ns, PBGA152
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
WEDPNF8M722V-1010BI 制造商:WEDC 制造商全稱:White Electronic Designs Corporation 功能描述:8Mx72 Synchronous DRAM + 16Mb Flash Mixed Module Multi-Chip Package
WEDPNF8M722V-1010BM 制造商:WEDC 制造商全稱:White Electronic Designs Corporation 功能描述:8Mx72 Synchronous DRAM + 16Mb Flash Mixed Module Multi-Chip Package
WEDPNF8M722V-1012BC 制造商:WEDC 制造商全稱:White Electronic Designs Corporation 功能描述:8Mx72 Synchronous DRAM + 16Mb Flash Mixed Module Multi-Chip Package
WEDPNF8M722V-1012BI 制造商:WEDC 制造商全稱:White Electronic Designs Corporation 功能描述:8Mx72 Synchronous DRAM + 16Mb Flash Mixed Module Multi-Chip Package
WEDPNF8M722V-1012BM 制造商:WEDC 制造商全稱:White Electronic Designs Corporation 功能描述:8Mx72 Synchronous DRAM + 16Mb 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)。

采購需求

(若只采購一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購

我的聯(lián)系方式

*
*
*