參數(shù)資料
型號(hào)： UPD488448FB-C80-45-DQ1
廠(chǎng)商： NEC Corp.
英文描述： 128 M-bit Direct Rambus⑩ DRAM
中文描述： 128 M位DRAM的直接Rambus的⑩
文件頁(yè)數(shù)： 24/80頁(yè)
文件大?。?/td> 1902K
代理商： UPD488448FB-C80-45-DQ1
Data Sheet M14837EJ3V0DS00
24
μ
PD488448 for Rev. P
12. Precharge Mechanisms
Figure 12-1 shows an example of precharge with the ROWR packet mechanism. The PRER command must occur
a time t
RAS
after the ACT command, and a time t
RP
before the next ACT command. This timing will serve as a
baseline against which the other precharge mechanisms can be compared.
Figure 12-1 Precharge via PRER Command in ROWR Packet
CTM/CFM
DQA7..0
DQB7..0
COL4
..COL0
ROW2
..ROW0
T
0
T
4
T
8
T
12
T
1
T
5
T
9
T
13
T
2
T
6
T
10
T
14
T
3
T
7
T
11
T
15
T
16
T
20
T
24
T
28
T
17
T
21
T
25
T
29
T
18
T
22
T
26
T
30
T
19
T
23
T
27
T
31
T
32
T
36
T
40
T
44
T
33
T
37
T
41
T
45
T
34
T
38
T
42
T
46
T
35
T
39
T
43
T
47
ACT a0
PRER a5
t
RAS
t
RC
a0 = {Da,Ba,Ra}
a5 = {Da,Ba}
b0 = {Da,Ba,Rb}
t
RP
ACT b0
Figure 12-2 (top) shows an example of precharge with a RDA command. A bank is activated with an ROWA packet
on the ROW pins. Then, a series of four dualocts are read with RD commands in COLC packets on the COL pins.
The fourth of these commands is a RDA, which causes the bank to automatically precharge when the final read has
finished. The timing of this automatic precharge is equivalent to a PRER command in an ROWR packet on the ROW
pins that is offset a time t
OFFP
from the COLC packet with the RDA command. The RDA command should be treated
as a RD command in a COLC packet as well as a simultaneous (but offset) PRER command in an ROWR packet
when analyzing interactions with other packets.
Figure 12-2 (middle) shows an example of precharge with a WRA command. As in the RDA example, a bank is
activated with an ROWA packet on the ROW pins. Then, two dualocts are written with WR commands in COLC
packets on the COL pins. The second of these commands is a WRA, which causes the bank to automatically
precharge when the final write has been retired. The timing of this automatic precharge is equivalent to a PRER
command in an ROWR packet on the ROW pins that is offset a time t
OFFP
from the COLC packet that causes the
automatic retire. The WRA command should be treated as a WR command in a COLC packet as well as a
simultaneous (but offset) PRER command in an ROWR packet when analyzing interactions with other packets. Note
that the automatic retire is triggered by a COLC packet a time t
RTR
after the COLC packet with the WR command
unless the second COLC contains a RD command to the same device. This is described in more detail in Figure 15-
1.
Figure 12-2 (bottom) shows an example of precharge with a PREX command in an COLX packet. A bank is
activated with an ROWA packet on the ROW pins. Then, a series of four dualocts are read with RD commands in
COLC packets on the COL pins. The fourth of these COLC packets includes an COLX packet with a PREX
command. This causes the bank to precharge with timing equivalent to a PRER command in an ROWR packet on
the ROW pins that is offset a time t
OFFP
from the COLX packet with the PREX command.
相關(guān)PDF資料
PDF描述
UPD488448FB-C80-45-DQ2 128 M-bit Direct Rambus⑩ DRAM
UPD488448FB-C71-45-DQ1 128 M-bit Direct Rambus⑩ DRAM
UPD488448FB-C71-45-DQ2 128 M-bit Direct Rambus⑩ DRAM
UPD488448FB-C60-53-DQ2 128 M-bit Direct Rambus⑩ DRAM
UPD488448FF-C80-45-DQ1 128 M-bit Direct Rambus⑩ DRAM
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
UPD4990AG-A 制造商:Renesas Electronics 功能描述:Cut Tape
UPD4991ACX-A 制造商:Renesas Electronics Corporation 功能描述:
UPD4992CX-A 制造商:Renesas Electronics 功能描述:Cut Tape
UPD50256CP15 制造商:HIT 功能描述:50256 HITACHI'86 SMT N9F8A
UPD50256CP-15 制造商:HIT 功能描述:50256 HITACHI'86 SMT N9F8A
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

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

*型號(hào) *數(shù)量 廠(chǎng)商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*