- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄375767 > FDC37N958FRTQFP (Electronic Theatre Controls, Inc.) DIODE ZENER SINGLE 200mW 5.1Vz 5mA-Izt 0.0588 2uA-Ir 2 SOD-323 3K/REEL PDF資料下載
參數(shù)資料
| 型號： | FDC37N958FRTQFP |
| 廠商： | Electronic Theatre Controls, Inc. |
| 英文描述： | DIODE ZENER SINGLE 200mW 5.1Vz 5mA-Izt 0.0588 2uA-Ir 2 SOD-323 3K/REEL |
| 中文描述： | 筆記本電腦的I / O控制器，具有增強型鍵盤和系統(tǒng)控制 |
| 文件頁數(shù)： | 81/316頁 |
| 文件大?。?/td> | 999K |
| 代理商： | FDC37N958FRTQFP |
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頁當前第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頁第229頁第230頁第231頁第232頁第233頁第234頁第235頁第236頁第237頁第238頁第239頁第240頁第241頁第242頁第243頁第244頁第245頁第246頁第247頁第248頁第249頁第250頁第251頁第252頁第253頁第254頁第255頁第256頁第257頁第258頁第259頁第260頁第261頁第262頁第263頁第264頁第265頁第266頁第267頁第268頁第269頁第270頁第271頁第272頁第273頁第274頁第275頁第276頁第277頁第278頁第279頁第280頁第281頁第282頁第283頁第284頁第285頁第286頁第287頁第288頁第289頁第290頁第291頁第292頁第293頁第294頁第295頁第296頁第297頁第298頁第299頁第300頁第301頁第302頁第303頁第304頁第305頁第306頁第307頁第308頁第309頁第310頁第311頁第312頁第313頁第314頁第315頁第316頁
SMSC DS – FDC37N958FR
Page 75
Rev. 09/01/99
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 79 due to its limitation of issuing a
maximum of 80 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 36
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 field 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.
For the Write Data case, the FDC activates Write
Gate at the beginning of the sync field under the
conventional mode. The controller then writes a
new sync field, data address mark, data field, and
CRC. With the pre-erase head of the
perpendicular drive, the write head must be
activated in the Gap2 field to insure a proper write
of the new sync field. For the 1 Mbps
perpendicular mode (WGATE = 1, GAP = 1), 38
bytes will be written in the Gap2 space. Since the
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| FDC40-12D05 | CONNECTOR,IDC PLUG,40 CONTACTS 1A,SHROUDED W/O EARS |
| FDC40-12D12 | CONN,IDC,PLUG,50 CONTACTS, 1A,SHROUDED W/O EARS |
| FDC40-12D15 | Isolated and Regulated 40 WATT Modular DC/DC Converters |
| FDC40-12D3305 | Isolated and Regulated 40 WATT Modular DC/DC Converters |
| FDC40-12S05 | Isolated and Regulated 40 WATT Modular DC/DC Converters |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| FDC37N971TQFP WAF | 制造商:SMSC 功能描述: |
| FDC37N972 | 制造商:SMSC 制造商全稱:SMSC 功能描述:Advanced Notebook I/O Controller with Enhanced Keyboard Control and System Management |
| FDC37N972FBGA | 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:SMSC 功能描述: |
| FDC37N972FBGA WAF | 制造商:SMSC 功能描述: |
| FDC37N972TQFP | 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:SMSC 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復。