- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄358934 > LPC47M112 (SMSC Corporation) ENHANCED SUPER I/O CONTROLLER WITH LPC INTERFACE PDF資料下載
參數(shù)資料
| 型號： | LPC47M112 |
| 廠商： | SMSC Corporation |
| 英文描述： | ENHANCED SUPER I/O CONTROLLER WITH LPC INTERFACE |
| 中文描述： | 增強(qiáng)的超級I / O控制器，LPC接口 |
| 文件頁數(shù)： | 62/228頁 |
| 文件大?。?/td> | 1269K |
| 代理商： | LPC47M112 |
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頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁當(dāng)前第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁第117頁第118頁第119頁第120頁第121頁第122頁第123頁第124頁第125頁第126頁第127頁第128頁第129頁第130頁第131頁第132頁第133頁第134頁第135頁第136頁第137頁第138頁第139頁第140頁第141頁第142頁第143頁第144頁第145頁第146頁第147頁第148頁第149頁第150頁第151頁第152頁第153頁第154頁第155頁第156頁第157頁第158頁第159頁第160頁第161頁第162頁第163頁第164頁第165頁第166頁第167頁第168頁第169頁第170頁第171頁第172頁第173頁第174頁第175頁第176頁第177頁第178頁第179頁第180頁第181頁第182頁第183頁第184頁第185頁第186頁第187頁第188頁第189頁第190頁第191頁第192頁第193頁第194頁第195頁第196頁第197頁第198頁第199頁第200頁第201頁第202頁第203頁第204頁第205頁第206頁第207頁第208頁第209頁第210頁第211頁第212頁第213頁第214頁第215頁第216頁第217頁第218頁第219頁第220頁第221頁第222頁第223頁第224頁第225頁第226頁第227頁第228頁
SMSC DS – LPC47M192
Page 62
Rev. 03/30/05
DATASHEET
DIR
0
1
ACTION
Step Head Out
Step Head In
The Relative Seek command differs from the Seek command in that it steps the head the absolute number of tracks
specified in the command instead of making a comparison against an internal register. The Seek command is good
for drives that support a maximum of 256 tracks. Relative Seeks cannot be overlapped with other Relative Seeks.
Only one Relative Seek can be active at a time. Relative Seeks may be overlapped with Seeks and Recalibrates. Bit
4 of Status Register 0 (EC) will be set if Relative Seek attempts to step outward beyond Track 0.
As an example, assume that a floppy drive has 300 useable tracks. The host needs to read track 300 and the head
is on any track (0-255). If a Seek command is issued, the head will stop at track 255. If a Relative Seek command is
issued, the FDC will move the head the specified number of tracks, regardless of the internal cylinder position register
(but will increment the register). If the head was on track 40 (d), the maximum track that the FDC could position the
head on using Relative Seek will be 295 (D), the initial track + 255 (D). The maximum count that the head can be
moved with a single Relative Seek command is 255 (D).
The internal register, PCN, will overflow as the cylinder number crosses track 255 and will contain 39 (D). The
resulting PCN value is thus (RCN + PCN) mod 256. Functionally, the FDC starts counting from 0 again as the track
number goes above 255 (D). It is the user’s responsibility to compensate FDC functions (precompensation track
number) when accessing tracks greater than 255. The FDC does not keep track that it is working in an “extended
track area” (greater than 255). Any command issued will use the current PCN value except for the Recalibrate
command, which only looks for the TRACK0 signal. Recalibrate will return an error if the head is farther than 255 due
to its limitation of issuing a maximum of 256 step pulses. The user simply needs to issue a second Recalibrate
command. The Seek command and implied seeks will function correctly within the 44 (D) track (299-255) area of the
“extended track area”. It is the user’s responsibility not to issue a new track position that will exceed the maximum
track that is present in the extended area.
To return to the standard floppy range (0-255) of tracks, a Relative Seek should be issued to cross the track 255
boundary.
A Relative Seek can be used instead of the normal Seek, but the host is required to calculate the difference between
the current head location and the new (target) head location. This may require the host to issue a Read ID command
to ensure that the head is physically on the track that software assumes it to be. Different FDC commands will return
different cylinder results which may be difficult to keep track of with software without the Read ID command.
Perpendicular Mode
The Perpendicular Mode command should be issued prior to executing Read/Write/Format commands that access a
disk drive with perpendicular recording capability. With this command, the length of the Gap2 field and VCO enable
timing can be altered to accommodate the unique requirements of these drives. Table 27 describes the effects of the
WGATE and GAP bits for the Perpendicular Mode command. Upon a reset, the FDC will default to the conventional
mode (WGATE = 0, GAP = 0).
Selection of the 500 Kbps and 1 Mbps perpendicular modes is independent of the actual data rate selected in the
Data Rate Select Register. The user must ensure that these two data rates remain consistent.
The Gap2 and VCO timing requirements for perpendicular recording type drives are dictated by the design of the
read/write head. In the design of this head, a pre-erase head precedes the normal read/write head by a distance of
200 micrometers. This works out to about 38 bytes at a 1 Mbps recording density. Whenever the write head is
enabled by the Write Gate signal, the pre-erase head is also activated at the same time. Thus, when the write head is
initially turned on, flux transitions recorded on the media for the first 38 bytes will not be preconditioned with the pre-
erase head since it has not yet been activated. To accommodate this head activation and deactivation time, the
Gap2 field is expanded to a length of 41 bytes. The Format Fields table illustrates the change in the Gap2 field size
for the perpendicular format.
On the read back by the FDC, the controller must begin synchronization at the beginning of the sync field. For the
conventional mode, the internal PLL VCO is enabled (VCOEN) approximately 24 bytes from the start of the Gap2
field. But, when the controller operates in the 1 Mbps perpendicular mode (WGATE = 1, GAP = 1), VCOEN goes
active after 43 bytes to accommodate the increased Gap2 field size. For both cases, and approximate two-byte
cushion is maintained from the beginning of the sync field for the purposes of avoiding write splices in the presence of
motor speed variation.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LPC47M112-MC | ENHANCED SUPER I/O CONTROLLER WITH LPC INTERFACE |
| LPC47M112-MW | ENHANCED SUPER I/O CONTROLLER WITH LPC INTERFACE |
| LPC47N252-SD | Advanced Notebook I/O Controller with On-Board FLASH |
| LPC47N252-SG | Advanced Notebook I/O Controller with On-Board FLASH |
| LPC47M172-NR | ADVANCED I/O CONTROLLER WITH MOTHERBOARD GLUE LOGIC |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LPC47M112_07 | 制造商:SMSC 制造商全稱:SMSC 功能描述:Enhanced Super I/O Controller with LPC Interface |
| LPC47M112-MC | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| LPC47M112-MW | 功能描述:以太網(wǎng) IC Enhanced Super I/O Cntrl LPC Interface RoHS:否 制造商:Micrel 產(chǎn)品:Ethernet Switches 收發(fā)器數(shù)量:2 數(shù)據(jù)速率:10 Mb/s, 100 Mb/s 電源電壓-最大:1.25 V, 3.45 V 電源電壓-最小:1.15 V, 3.15 V 最大工作溫度:+ 85 C 封裝 / 箱體:QFN-64 封裝:Tray |
| LPC47M133-NC | 制造商:SMSC 功能描述: |
| LPC47M140-NC | 制造商:SMSC 制造商全稱:SMSC 功能描述:128 PIN ENGANCED SUPER I/O CONTROLLER WITH AN LPC INTERFACE AND USB HUB |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。