- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄376836 > DP84422N DRAM Controller PDF資料下載
參數(shù)資料
| 型號： | DP84422N |
| 英文描述： | DRAM Controller |
| 中文描述： | DRAM控制器 |
| 文件頁數(shù)： | 20/46頁 |
| 文件大小： | 644K |
| 代理商： | DP84422N |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第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頁當(dāng)前第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頁第43頁第44頁第45頁第46頁
6.0 Refresh Modes
The DP8440/41 support auto-internal refresh, and external-
ly control refresh. The DP8440/41 arbitrates between re-
freshes and accesses and guarantees precharge timings af-
ter every access and refresh. The DRAM controller will nev-
er interrupt an access in progress to do a refresh, nor will it
interrupt a refresh in progress when an access is requested.
After every refresh the DRAM controller will guarantee the
programmed precharge time before RAS can assert for a
new access or for a second refresh. The refresh period can
be programmed for 15
m
s or for 120
m
s.
6.1 AUTO-INTERNAL REFRESH
This refresh scheme is completely transparent to the CPU.
The DP8440/41 will refresh the DRAM every 15
m
s or
120
m
s, depending on the programming selection. When the
refresh counter expires (every 15
m
s or 120
m
s) the RFRQ
output asserts. On the next rising edge of clock RFIP as-
serts and, one clock period later, RASs assert. RFIP ne-
gates on the same clock edge that RASs negate. If the user
is doing long page or burst accesses, the DP8440/41 will
keep track of up to 6 missed refreshes. At the end of the
access the DRAM controller will burst refresh the locations
missed during the access.
TL/F/11718–10
FIGURE 14. Autointernal Refresh (2T of RAS Low and Precharge)
20
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| DP84432J | DRAM Controller |
| DP84432N | DRAM Controller |
| DP8472 | Floppy Disk Controller |
| DP8472J | Floppy Disk Controller |
| DP8472N | Floppy Disk Controller |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DP84422N/A+ | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:DRAM Controller |
| DP84422N/B+ | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:DRAM Controller |
| DP84432J | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:DRAM Controller |
| DP84432J/A+ | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:DRAM Controller |
| DP84432N | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:DRAM Controller |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。